UNIVERSITI PUTRA MALAYSIA

SAMPLING SYNTHESIS TECHNIQUE APPLIED FOR THE DIGITAL GENERATION OF MUSICAL TONES OF

MALAY FOLK INSTRUMENTS

ANG YAW FENG

FEM 2001 6

SAMPLING SYNTHESIS TECHNIQUE APPLIED FOR THE DIGITAL GENERATION OF MUSICAL TONES OF

MALAY FOLK INSTRUMENTS

By

ANGYAWFENG

Thesis Submitted in Fulfilment of the Requirement for the Degree of Master of Science in the Faculty of Human Ecology

Universiti Putra Malaysia

April 2001

Abstract of thesis presented to the Senate ofUniversiti Putra Malaysia in fufilment of the requirement for the degree of Master of Science.

SAMPLING SYNTHESIS TECHNIQUE APPLIED FOR THE DIGITAL GENERATION OF MUSICAL TONES OF MALAY FOLK

INSTRUMENTS

By

ANG YAW FENG

April 2001

Chairman: Minni Ang Kim Huai, Ph.D.

Faculty: Human Ecology

A random survey of commercial synthesisers available shows that sampled

sounds of Malay folk instruments such as the rebab, seruling and others are lacking in

both fonns of software or hardware, in sharp contrast to Western classical instrument

sounds where similar materials are in abundance. This study attempts to create

original sound banks of selected Malay folk instruments in two fonnats, SoundFonts

(SFs) and the Downloadable Sounds (DLS) fonnats by application of the sampling

synthesis method and analysis of the waveforms of selected instruments. The

recorded sound samples of individual selected Malay folk instruments are organised

11

and sequentially edited according to established procedures of trimming,

normalisation, conversion and pitch shifting. The identification of the ADSR

envelope and frequency components of specific instruments' waveform is also carried

out. Finally, the creation of SoundFonts and DLS instruments is undertaken. As a

result of this study, the following have been achieved: a) The production of high

quality and realistic soft sound banks of selected Malay folk instruments in the

SoundFonts (SFs) and the Downloadable Sounds (DLS) formats. b) A detailed

analysis of waveforms and frequency components produced by selected Malay folk

instruments. It is hoped that these sound banks would be useful as a source of musical

tones, applicable for playback of MIDI sequences orchestrated utilising Malay folk

instruments, for use by composers as well as commercial products such as

synthesisers, samplers and keyboards.

iii

Abstrak tesis yang dikernukakan kepada Senat Universiti Putra Malaysia sebagai rnernenuhi keperluan untuk ijazah Master Sains.

TEKNIK SINTESIS PERSAMPELAN UNTUK PENJANAAN SECARA DIGITAL NADA ALAT MUZIK TRADISI MELAYU

Oleh

ANG YAW FENG

April 2001

Pengerusi: Minni Ang Kim Huai, Ph.D.

FakuIti: Ekologi Manusia

Satu kajian sernasa secara rawak ke atas sintesiser kornersial menunjukkan

ketiadaan sarnpel bunyi alat muzik tradisi Melayu seperti rebab, seruling dan lain-

lain, rnahupun dalam bentuk perisian atau perkakasan. Ini arnat berbeza dengan

sarnpel bunyi alat rnuzik Barat yang rnudah diperolehi dalarn konteks perisian dan

perkakasan yang sarna. Kajian ini bertujuan mencipta arkib digital alat muzik tradisi

Melayu dalam dua format, SoundFonts (SFs) dan Downloadable Sounds (DLS),

secara aplikasi teknik sintesis persarnpelan termasuk analisis gelombang. Bunyi alat

rnuzik tradisi Melayu yang dirakarnkan disunting, diikuti dengan prosedur

iv

pemerosesan berikut: 'trimming', 'normalisation', 'conversion' dan

perubahan pic. Langkah ini diikuti dengan prosedur analisis gelombang yang

merangkumi pengenalpastian komponen frekuensi yang hadir di dalam spektrum alat

muzik tradisi Melayu yang terpilih serta sampul ADSR untuk setiap gelombang.

Proses ini berakhiri dengan penciptaan SoundFonts and alat-alat DLS. Kajian ini telah

berjaya mencapai: a) Arkib digital nada alat muzik tradisi Melayu dalam format SFs

serta DLS; b) Analisis gelombang serta komponen frekuensi yang wujud di dalam

spektrum alat muzik tradisi Melayu. Hasil projek ini boleh digunakan oleh pencipta

muzik serta produk komersil seperti sintesiser, sampler dan alat kibod.

v

ACKNOWLEDGEMENTS

I would like to register my gratitude to my mentor and supervisor, Dr. Minni

Ang Kim Huai whose advice, encouragement, guidance, and supervision made this

study possible. I am also deeply indebted to her for painstakingly going through the

manuscript. Next, I would like to extend my heartfelt thanks to my second

supervisor, Mr Paul Isitt for his invaluable feedback and suggestions, especially

regarding the method in creating SoundFonts banks using the Vienna software. My

special thanks to my third supervisor, Mr. Chan Cheong Jan for his ideas and input

throughout this study. I would like to thank the National Arts Academy or Akademi

Seni Kebangsaan (ASK), for allowing me to record all my samples there. Also, the

most noted player of the ASK, Encik Mohd. Kamarulbahri Hussin for his assistance

in spending much of his precious time to play all the chosen Malay folk instruments. I

am also grateful to Encik Hamzah Awang Amat, a very skilful player with more than

1 0 years of experience in making Malay traditional instruments in Malaysia, for

preparing the various instruments used in this research project. My thanks are also

accorded to Mr. Rick Craig Shriver for imparting to me his knowledge of recording

techniques. I am also indebted to the Universiti Putra Malaysia Graduate School for

the Pasca Siswazah Award scheme, which supported this study throughout the two

years duration. Last but not least, I would like to extend my gratitude to all my

research colleagues, Bee Suan, Julie, Yoke Fun and Ee Lyn, for their understanding

and co-operation, and my parents for their encouragement, support and love.

VI

I certIfy that an ExammatIOn CommIttee met on 29th April 2001 to conduct the final exammatIOn of Ang Yaw Feng on her Master of SCIence thesls entltled "Samphng SyntheSIS TechnIque ApplIed for the DIgItal GeneratIOn Of MUSIcal Tones of Malay Folk Instruments" m accordance WIth Umversltl Putra MalaYSIa (HIgher Degree) Act 1980 and UmversltI Putra MalaYSIa (HIgher Degree) RegulatIOn 198 1 . The CommIttee recommends that the candIdate be awarded the relevant degree Members of the ExammatIOn CommIttee are as follows

Martha Lee Jm AI, M A Faculty of Human Ecology UmversltI Putra MalaYSIa (ChaIrman)

Mmm Ang KIm HUaI, Ph D Faculty of Human Ecology Umversitl Putra MalaYSIa (Member)

Paul ISltt, MMus Faculty of Human Ecology Umverslty Putra MalaYSIa (Member)

Chan Cheong Jan, M Ed Mus Faculty of Human Ecology Umverslty Putra MalaYSIa (Member)

AINI IDERIS, Ph D, Professor / Dean of Graduate School, Umvelsltl Putra MalaYSIa

Date 3 0 MAY 2001,

VII

This Thesis was submitted to the Senate of Universiti Putra Malaysia has been accepted as fulfillment of the requirements for the degree of Master of Science.

viii

AINI IDERIS, Ph. D, Professor / Dean of Graduate School, Universiti Putra Malaysia.

Date:

DECLARATION FORM

I hereby declare that the thesis is based on my original work except for quotations and citations which have been duly acknowledged. I also declare that it has not been previously or concurrently submitted for any other degree at UPM or other institutions.

IX

Candidate. ANG YAW FENG

Date: 1ft /s I 0 f

TABLE OF CONTENTS

Page

ABSTRACT ........ , ..... '" ., ..... , .......... '" .. , .... ,. " ................. ,. .. .... ......... .... 11 ABSTRAK......................................................................................... iv ACKNOWLEDGEMENTS..................................................................... VI

APPROV AL SHEETS ................................. , .......................... , ... . .. . ....... Vll

DECLARATION FORM........................................................................ IX

LIST OF TABLES........................................................................ ........ XlI

LIST OF FIGURES ...................................... '" ., ..................... ,. .. .... ... .... XIV

LIST OF ABBREVIATIONS................................................................... XVI

CHAPTER

I INTRODUCTION ............................................................. . Statement of the Problem ..................................................... .

1 3

Objective of the Study.......................... ............. .... . . . . . . . . . .. . . .. 4 Significance of the Study.......................... ......................... ... 4 Design of the Study............................................ ............. . .. . 5 Organisation of the Thesis.................................................... 5

n LITERATURE REVIEW................................... ................... 7 Preservation of Musical Instruments Culture................. ........... .... 7 Theory of Sampling Synthesis............................. ................... 11

The Process of Digital Sampling............................. ......... 11 Critical Factors of Creating Good Samples ....... . ..... ... . ........ 13 Sampling Synthesis Research ...................................... ,. . 18

Soft Sound Bank Formats ....................................... ,. ... .. . .. . ... 20 SoundFonts (SFs) ....................... ..... . . . . . . . . . . . . . .. ... . .. . . . . ... 21 Downloadable Sound (DLS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . 26

Conclusion.............................................................. ......... 30

III METHODOLOGy .... '" . . .. . . .. ,. .. . .. . .. .. . . . . . . . . . . . .. . . . . .... . .. . . . . .. . .... 3 1 Sample Recording. ... . . . . . .... . . . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . . . . . . . . . . .. .. 31

Prerequisites.............................................................. 31 Recording Set Up ................. '" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...... 34 Recording Section................................................ ......... 37

Sample Organisation ..... '" ..... '" ... , .............. , ... .. ......... . ..... .... 38 Sound Editing........... .......................................................................... 38

TnmmIng................................................................. 39 Normalisation......................................................... .. .. 40 Conversion............................................ .... ............. ... 41

x

Pitch shifting ........... '" '" ......................... , .... .. .... ........... 41 Wavefonn Analysis .............................. '" ................ , '" ........ 43

ADSR Envelope Identification........ ....... . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Frequency Components Identification . . . . . . . . " . . . . " '" . . . . . . . . . . . . . 45

SoundFonts and DLS Instrument Creation. . . . . . ... . . . . . . . . . . . . . . . . . . . . . . . . . . 49 SoundFonts Creation . . . . . . . . '" . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 DLS Instrument Creation................. .................................... 6 1

Conclusion . . . . . . . . . . . . . . . . . . . . '" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

IV RESULTS AND DISCUSSION............................................. 69 The Recording of selected Malay Folk Instruments....................... 69 The ADSR Envelope Analysis............. . . .... . .. ..... ..... . . . .. .. . . .. .. . . ... . ... 70 The Frequency Analysis.......................................... . . . . . . . . . . . . . . . . . 76 SoundFont banks and DLS instrument Creation............... . . . . . . . . . . .. . 79 Discussion .......................... '" . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

Hard disk space and RAM optimisation....... . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Realism of tone production........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 Accuracy of intonation and error-correction methods.............. 83 Comparison between SoundFonts and DLS....... .... . . . . . . . . . . . . . . 84

Conclusion ..... , . . . , . " . . . '" . . , . " . . , . . . , . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

V CONCLUSION AND SUGGESTIONS FOR FURTHER STUDy........................................................................... 86 Summary of the Thesis.. ........... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 Conclusion ............................................. '" . . . . . . . . . . . . . . . . . . . . . . . 89 Suggestion for Further Study. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

BIBLIOGRAPHy................................................................................... 9 1

APPENDICES...................................................................................... 99 A List of Malay Folk Instruments Wave Files . . . .. . . . . . . .. . . . . . . . . . . . . .... . . . . '" . . . . 100 B List of Malay Folk Instruments Image Files.. .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 C Wavefonn Envelope of the Malay Folk Instruments ............... , . . . . . . . . . . . . . 105 D Tables of Frequency Analysis Results.................. ......... . . . . . . . . . . . . . . . . . . . . 1 15 E SoundFont Bank and DLS Instrument Creation Results . . . . . . . '" . . .. . . . . . . . . . . 145 F The Frequency Value and Midi Number of Each Note ........................ " 160 G General Infonnation on the Malay Folk Instruments............................. 161 H Definitions............................................................................. 17 1 I Publication Arising from this Research Project.... . . . . . . . . . .. . . . . . . . .. . . . . . . . . . .. . 18 1

BIODATA OF AUTHOR........................................................................ 182

Xl

LIST OF TABLES

Table Page

1 The Sample Rates versus the Nyquist Frequency.................... .... . . . . 15 2 The Number of Bits versus the SNR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... . . . 17 3 The Key Group Assignment of Different Malay Folk Instruments....... 66 4 The Duration of Each ADSR Portion of the Malay Folk Instruments.. .. 70 5 ADSR Waveforms Types......................................................... 72 6 List of Stereo Wave Files. ... ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 100 7 List of Mono Wave Files......................................................... 102 8 List of Photographic Images........ . ... .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 9 Frequency Analysis Result of Gambus [C3} . . . . . . . . . .. . . . . . .. . . . . ... . . . . . ... . 116

10 Frequency Analysis Result of Rebab [C4} . . . . . . . . . . . . . . . . . . . . . . . . ...... ..... .. 116 1 1 Frequency Analysis Result of Seruling [C5} . . . . . . . . . . . . . . . . . . . . . . . . ... . . . .... 117 12 Frequency Analysis Result of Serunai [C5} . . . . . . . . . ... ........ . . . . . . . . . . . . .. . . . . . 117 13 Frequency Analysis Result of Angklung Anak. ..... . . . . . . . . . . . . . . . . . . . . . . . . . . 118 14 Frequency Analysis Result of Angklung Ibu . . ........... . . . . . . . . . . . . . . . . . . . . . . 118 15 Frequency Analysis Result of Gendang Anak (Cak) ...... . . ..... .. .. . ...... 119 16 Frequency Analysis Result of Gendang Anak (Ting) .. . .. .... . . . . ... ... . . .. 120 17 Frequency Analysis Result of Gendang Anak (Tak) .. . . . . . . . . . . . . . . . . . . . . . . . 121 18 Frequency Analysis Result of Gendang Ibu (Pak) .. .... ..... .. ....... .... . . 122 19 Frequency Analysis Result of Gendang Ibu (Duh) ......... ........ .... . .... 123 20 Frequency Analysis Result of Gendang Ibu (Tak) ... . .. ..... ...... .... . ..... 124 21 Frequency Analysis Result of Gedombak Anak (Cak) ............. . ... . . . .. 125 22 Frequency Analysis Result of Gedombak Anak (Doh) .. .... ..... ....... . .. 126 23 Frequency Analysis Result of Gedombak Anak (Ting) . . .... . . . . . . . . . . ... . . 127 24 Frequency Analysis Result of Gedombak Ibu (Cak) . ........ .. . .... ....... . l38 25 Frequency Analysis Result of Gedombak Ibu (Doh) .. . . . . . .. . .. ............ 129 26 Frequency Analysis Result of Gedombak Ibu (Ting) .......... . ...... . . . .... l30 27 Frequency Analysis Result of Geduk Anak. . .... . ... . . . . . . . . . . . . . . . . . . . . . . . . . . 130 28 Frequency Analysis Result of Geduk Ibu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 29 Frequency Analysis Result of Kompang (Cak) .. .............. . .. ..... .. .... 131 30 Frequency Analysis Result of Kompang (Doh) .... .. . ... .. . . . . . . . . . . . . . . . ... 132 3 1 Frequency Analysis Result of Kompang (Tak) " . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 32 Frequency Analysis Result of Rebana (Doh) . . . .. . .. . . . . . . . . . . . . . . . . . . . . . . . . . 134 33 Frequency Analysis Result of Rebana (Gong) .. ..... . . .... ... . .... . .... .... . l35 34 Frequency Analysis Result of Rebana (Pak) .. ...... . .. .. ...... ... . .. .. .. .... 136 35 Frequency Analysis Result of Rebana (Tak) . . . .. ..... .. .... .......... . .. .... 137 36 Frequency Analysis Result of Canang Anak. . . . . . .... . . . . . . . . . . . . . . . . . . . . . . . . 138 37 Frequency Analysis Result of Canang Ibu. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 38 Frequency Analysis Result of Kesi (Cap) .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 39 Frequency Analysis Result of Kesi (Ong) . . ...... . . . ................... ...... 140

xii

(Continued)

40 Frequency Analysis Result of Gong Anak.. ... .. .. . . . ...... .... . .. ........ .... 142 41 Frequency Analysis Result of Gong Ibu.. . .. .. . . . . . . ... . . . . . . . . . . . . . . . . .... . .. 142 42 Frequency Analysis Result of Gong Anak (Muted).. . . . . ..... . ... . . . . . . ..... 143 43 Frequency Analysis Result of Gong Ibu (Muted)... . . .. . . .. . . . . . . . . . . . . . . ... 145 44 Patches Created for the SFs of Individual Malay Instrument....... ........ 145 45 Patches Created for the DLS of Individual Malay Instrument............. 146 46 Patches Created for the "Malay Percussion" SFs... . . . . . . . . . . . . . . . . . . . . . . ... 146 47 Patches Created for the "Malay Percussion" DLS........................... 147 48 Patches Created for the "Malay" SFs..................... .................. . .. 147 49 Patches Created for the "Malay" DLS.................................... ..... 148 50 Patches Created for the "Malay Drums 1" SFs.............................. 148 5 1 Patches Created for the "Malay Drums 1" DLS.............................. 148 52 Parameter Details for the "Malay" SFs........................................ 150 53 Parameter Details for the "Malay" DLS......................... ............. 15 1 54 Parameter Details for the "Malay Drums 1" and "Malay Drums 2"

SFs..................................................................... .......... . .... 152 55 Parameter Details for the "Malay Drums 1" and "Malay Drums 2"

DLS................................................................................ 153 56 Parameter Details for the Gedombak of "Malay Drums 2" SFs and

DLS................................................................................. 154 57 Parameter Details for other Malay Drums of "Malay Drums 2" SFs

and DLS .. . ........... . . . .......................................................... 154 58 Parameter Details of "Malay" SFs (High Quality)........................... 155 59 Parameter Details of "Malay" DLS. (High Quality)......................... 156 60 List of Frequency Value and Midi Number for Each Note................. 158

xiii

LIST OF FIGURES

Figure Page

1 Time-Varying Voltage Sampled Periodically.................... ............ 12 2 An Overview of a Complete Sampling System........................... ... 13

3 The Sample Rate and Sample Resolution of Portion Waveform.... ...... 14 4 The Relationship between Preset, Instrument and Sample. ... . ... .. .... ... 25 5 A Diagram of the DLS Architecture.. ........... .............................. 27 6 The Digital Audio Engine ..................... , .. , . '" .... ..... ....... .... ... . .... 28 7 A Diagram of the Melodic Instrument Architecture.. ........ .... ........... 29 8 A Diagram of the Drum Kit Architecture...... .......... ...... .......... ... .... 29 9 The Position ofX-Y Coincident Miking.. ........... .... ...... .............. ... 35

10 Trimming a Sound Sample Waveform.. .... ... .... ... ...... ......... .... ....... 39 11 Normalisation of a Sound Sample Waveform................................. 40 12 The Pitch Bender Window.. ..... ......... ......................................... 43 13 An ADSR Amplitude Envelope ....... . ................... . .............. " ...... 44 14 Six Added Harmonics Derived from a Fundamental Frequency and the

Next Five Harmonics....... .. . ... .................................................. 46 15 The Spectrum of a Tone. ............ .......... ....... ...... ........ ............ ... 47 16 The SoundFont Tree View . . . ....................................... . ............ , 49 17 Keyboard Range List Box for Vienna SFs Editor......................... .. 52 18 Root-Key Number Setting..................... ................................... 53 19 Full View of the Rebab Waveform in Global Loop Marking Dialog

Box..................................................................................... 57 20 Incorrect Loop Point Results in Aliasing. ... ............... ......... ....... .... 59 21 Zero Crossing Technique Used in Defining Global Loop.............. .... 59 22 Two Additional Check Boxes in Layout of the Local Dialog Box for

Loop Marking .. . .. . ............... .. . .............................................. , 60 23 The Instrument Setting for a DLS Instrument.. .................. . .. , . ....... 63 24 The Region Setting for a DLS Instrument... .. ........... .... .. ....... .. . .... 63 25 Diagrammatic Representation of the Methodology.......................... 68 26 Three Types of ADSR Waveforms......... . ...... . . ......... ...... .... ....... 71 27 Difference in Waveform Shape between Angklung and Seruling,

Serunai or Rebab.................... ... .......................... . .. . ........ .... 74 28 Waveform Envelope of the Angklung Anak.. ................. ........... ..... 106 29 Waveform Envelope of the Angklung Ibu.................................... 106 30 Waveform Envelope of the Canang Anak.... ....... ........ ...... ........... 106 31 Waveform Envelope of the Canang Ibu. . . . . . . . . . . .... . .. ... . . . . .. . . . . .... .... 106 32 Waveform Envelope of the Gambus (Finger) [C3].. ...... ............ ..... 107 33 Waveform Envelope of the Gambus (Plectrum) [C3] ........ .. . .. ... ... ... 107 34 Waveform Envelope of the Gedombak Anak (Cak)......................... 107 35 Waveform Envelope of the Gedombak Anak (Dong) .... '" ......... . .. . ... 107

xiv

( Continued)

36 Wavefonn Envelope of the Gedombak Anak (Ting) ................ , ... .... 108 37 Wavefonn Envelope of the Gedombak Ibu (Cak)........... ... ... .... ... .... 108 38 Wavefonn Envelope of the Gedombak Ibu (Dong).............. ........ .... 108

39 Wavefonn Envelope of the Gedombak Ibu (Ting).. .............. ........... 108

40 Wavefonn Envelope of the Geduk Anak.. . . . . . . . . . . . . . . . . . . . . ... . . . . . . . . . . . ... 109

41 Waveform Envelope of the Geduk Ibu.... .. .. .. .. .. .. .. .. .. ..... ... ...... .. . ... 109

42 Waveform Envelope of the Gendang Anak (Cak).. ....... ............ ....... 109

43 Waveform Envelope of the Gendang Anak (Ting) ... . ......... . . . .. , ... ..... 109

44 Waveform Envelope of the Gendang Anak (Tak). ....... ....... ....... ...... 110

45 Wavefonn Envelope of the Gendang Ibu (Pak) ............................ , 110

46 Wavefonn Envelope of the Gendang Ibu (Duh)... .... ... ...... ..... ...... ... 110

47 Wavefonn Envelope ofthe Gendang Ibu (Tak)........ ...... ................. 110

48 Wavefonn Envelope of the Gong Anak (Muted)...... ........ ...... .... ..... 111

49 Wavefonn Envelope of the Gong Anak .............. , ........ , .... ...... ..... 111

50 Waveform Envelope of the Gong Ibu (Muted).. ....... .... ..... ..... ..... ... 111

51 Wavefonn Envelope of the Gong Ibu................ ......... ........... . . .... III

52 Wavefonn Envelope of the Kesi (Cap)......................................... 112

53 Wavefonn Envelope of the Kesi (Cing).............. ........... .... ....... .... 112

54 Wavefonn Envelope of the Kompang (Cak}.... .... ......... ... ......... ..... 112

55 Wavefonn Envelope of the Kompang (Doh}................................. 112

56 Wavefonn Envelope of the Kompang (Tak)....... ... ..... ........ .... ....... 113

57 Waveform Envelope of the Rebab [C4] .......... ............ .......... ...... 113

58 Waveform Envelope of the Rebana (Doh)....... ........... .... ..... ... ...... 113

59 Waveform Envelope of the Rebana (Gong). .... ........ .................. .... 113

60 Wavefonn Envelope of the Rebana (Pak) .... . ........ '" .. , ............ .... . 114

61 Wavefonn Envelope of the Rebana (Tak}..... .......... ....... ...... ........ 114

62 Wavefonn Envelope of the Seruling [C5].............. ...................... 114

63 Wavefonn Envelope of the Serunai [C5] .......... '" .... .... .......... ..... 114

xv

12-ET ADC ADR ADSR AR

CD-ROM DAT DAW DB DCA DFS DLS DVD Egs FM GM KHz LD LFO LSB MB Mbps MD MDM MIDI MMA MSB PC PCM RIFF SNR STFT

LIST OF ABBREVIATIONS

12-tone equal-tempered AJD converter or analogue to digital converter attack decay release attack, decay, sustain, release attack release compact disc read only memory digital audio tape digital audio workstations decibel digitally controlled amplifier digital full scale downloadable sounds specification. digital video disc or digital versatile disc envelope generators frequency modulation general MIDI kilohertz! thousands of cycles per second laser disc low frequency oscillator least significant byte megabytes megabits per second mini disc multi track digital multi-tracks musical instrument digital interface MIDI Manufacturer's Association most significant byte personal computer pulse code modulation resource interchange file format signal-to-noise ratio short-time Fourier transform

xvi

CHAPTER ONE

INTRODUCTION

Sampling is a process where sound [an analogue signal] is recorded digitally.

When sound is recorded into a sampler, it turns the audio waveform into a series of

binary numbers or bits [Os and Is], that can easily be shuffled around and

reassembled. This process is achieved with an electronic circuit called an analogue­

to-digital converter (AID converter or ADC for short). In contrast, analogue

recording is based on the voltage recorded as patterns of magnetisation in the oxide

particles of the recording tape. (Snyder, 1999). For instance, individual musical

instrument tones once recorded, can then be played back on a keyboard. These

individual tones, commonly referred to as "samples", could be stored on a CD­

ROM (Compact Disc-Read Only Memory) or hard disk, but are read in RAM

memory for speedy access.

The term sampling is derived from established notions of digital samples and

sampling rates. "Sampling Rates" in tum, refers to the number of samples that are

taken of an analogue signal per second. The more regularly samples are taken, the

better the result will be when the sample is played back (Roads, 1996). This is due to

the mechanics of recording devices capable of capturing tiny variations in the sound

waves more accurately. As a result, this produces higher fidelity recordings with less

distortions (Rubin, 1995).

2

Sampling thus has an edge over multiple wave cycling, in that it applies a

longer wavetable containing thousands of individual cycles - several seconds of pre­

recorded sounds, permitting the use of pointers within a sample to define internal

looping. It creates samples from live and pre-recorded materials. Recorded sound can

be stored in disks, or in the internal memory (Roads, 1996; Dodge & lerse, 1997).

The sample later can be spliced, copied, reversed, enveloped, cross-faded, looped,

sped up or manipulated in any combination of the above in order to change the

duration, pitch and timbre. Effects such as reverberation or flanging can also be

introduced in the wave-shaping process. As a result, it is usually used to create

sonorities and effects that would normally not be possible to achieve acoustically.

(Moore, 1996; Miranda, 1998). In effect, sampling synthesis permits the production

of rich, natural, and time-varying sounds useful for composition, live performance

and sound effects purposes. It has minimal flexibility since only few transformations

are possible at this level. (De Poli, 1996). The input signal is always the same, as it

is recorded. The input signal is a recorded sound resulting in the absence of the

control over life-like qualities of sounds that help enhance the perception of music.

Today, there are many different formats or arrangements of data used for

describing samples. Two of the most common are the SoundFonts (SFs) 2.0 format

patented by Creative Technology Limited, and the Downloaded Sounds (DLS) format

standardized by the MIDI Manufacturers Association (MMA). (Scheirer, 1999). The

primary objective of this study is to obtain original banks of sound samples of

selected Malay folk instruments in the form of these two formats. All the sound

3

samples can either be uploaded onto the internet or recorded into a CD-ROM for

further usage, as well as loaded into commercial synthesisers.

Malay folk instruments that have been chosen for this study are categorised

according to instrument families as follows: a) String instruments or chordophones':

gambus and rebab [Malay violin]; b) Wind instruments or aerophones2: seruling

[flute] and serunai; c) Percussion instruments: i) Membranophones3: gedombak,

geduk, gendang [bigger drums], kompang and rebana and ii) Idiophones4: angklung,

canang, kesi, and tetawak or gong.

Statement of the Problem

A random survey of commercial synthesisers available shows that

sampled sounds of Malay folk instruments such as the rebab, seruling and others

have yet to be found in any of these products whether in the form of software or

hardware. On the other hand, Western classical instruments sounds and other variety

of other sounds have long been sampled in those products. Also, no study has been

carried out on analysing the waveform of the sound produced by Malay folk

instruments to date.

I Chordophones refers to instruments using a stretched string as sound generator. 2 Aerophones are instruments producesing sound with a column of air. JMembranophones refers to instruments with stretched skin or other membrane for sound generation. 4Idiophones refers to instruments made up of material with self-generating sounds.

4

Objective of the Study

The primary objective of this study aims at obtaining a high quality sound

bank of Malay folk instruments in the SoundFonts (SFs) formats and the

Downloadable Sounds (DLS) by applying the sampling synthesis method, besides

obtaining an analysis of waveforms produced by each of the Malay folk instruments.

Significance of the Study

This study is primarily targeted towards the musician in the field of music

technology and manufacturers of musical instruments. By producing the sampled

sound of Malay folk instruments, it is hoped that composers will be able to utilise

these sound fonts, with Compact Disc (CD) quality sound of MIDI (Musical

Instrument Digital Interface) playback for their own compositions, particularly for

those who attempt to compose music using Malay folk instruments. In doing so, they

will be able to hear the immediate effects of the Malay folk instruments when they

use these instruments in their compositions, whilst manufacturers of commercial

musical instruments such as synthesisers, samplers and keyboards could hopefully

incorporate these realistic representations of eastern instruments into their products in

future.

5

Design of the Study

This study is divided into five mam sections. The sections are,

accordingly: sample recording, sample organisation, sound editing, wavefonn

analysis succeeeded by SoundFonts and DLS intruments creation.

Initally, the sound samples of the selected Malay folk instruments are

recorded onto Digital Audio Tape (DAT). After that, the sound samples are

transferred to computer hard disk, organised systematically into different catogories

and stored using descriptive file names. The wave files are then edited with the

trimming, nonnalisation, conversion and pitch shifting processes done at this stage5.

Later, the wavefonn of each different Malay folks instruments' sound sample is

analysed from two points of view: the ADSR envelope and the frequency

components. Finally, the SoundFonts and DLS instruments are created using the

software Vienna 2.3 and Direct Music Producer respectively.

Organisation of the Thesis

This thesis is organised into five chapters. Chapter two deals with the research

literature review, commencing with a discussion on the preservation of Malay folk

instruments culture, followed by an explanation of the theory of sampling synthesis,

the digital sampling process and critical factors in producing a good sample. This is

5 These terms will be explained in Chapter Three, when the methodology is described in detail

6

followed by a review of sampling synthesis from a historical and developmental

perspective, as well as current research trends. The chapter concludes with a

discussion on the two soft sound bank formats used in this research, SoundFonts

(SFs) and Downloadable Sounds (DLS).

Chapter Three deals in detail with the methodology of the whole study. This

chapter contains five main sections: sample recording methodology, sample

organisation, sound editing methodology, waveform analysis methodology and

finally, SoundFonts and DLS instruments creation methodology.

The fourth chapter contains results and discussions, including results of the

waveform analysis performed on the various samples. The SoundFonts and DLS

instruments created through this research are appended to this thesis in the form of a

CD-ROM. Background information on each of the Malay folk instruments selected is

presented as an appendix to the main text.

Conclusions of the research are presented in the last chapter, along with

suggestions for further studies. The following chapter presents the review of related

literature.

CHAPTER TWO

LITERATURE REVIEW

This chapter presents the literature review related to this study. It begins with a

discussion on the preservation of Musical instruments culture, followed by the theory of

sampling synthesis. This section is further subdivided into the digital sampling process

and critical factors involved in creating good samples. After that, sampling synthesis

research is considered. Finally, the chapter ends with a discussion on SoundFonts (SFs)

and Downloadable Sounds (DLS).

Preservation of Musical Instruments Culture

From the end of 19th century, efforts have been made by ethnomusicologists to

preserve culture through assembling primary sources from target fieldwork in various

ways: observation in fieldwork, music recordings and interviews, photographs, film and

video taping. In this regard, documentary recording has been vital in preserving

traditional music. Ethnomusicologists have used sound recording as an integral part of

their scholarly texts, instead of being limited to the written word, such as for musicology

work. Recording technology has provided the ethnomusicologist and musicologist the

means to preserve, duplicate and reshape raw data using the latest technology. In the

early days of culture preservation, the recording technology employed was mainly

analogue. Magnetic tape, open-reel, videotape and cassette were utilised in order to

capture the sound of traditional instruments (MaIm, 1992; Myers, 1990). The cassette

7

8

restricted signal-to-noise ratio (SNR) (Refer page 17) and limited frequency response,

both resulting from the narrow track width and slow tape speed, and these cumulate

in noisy recordings with background hiss.

In retrospect, it is little wonder that digital recording has dominated the

recording scene since the 1990s. One major advantage of digital recording is

generally providing high quality sound recording. Besides, recorded signals do not

degenerate with repeated playing. Furthermore, it is possible to generate copies from

the original with equal fidelity to the original. The emergence of attainable standards

in digital recording overcomes major problems prevalent in the days of analogue

recording, such as tape noise and distortion. In this respect, a vast majority of digital

recording systems are capable of detecting and eliminating interfering signals. Digital

techniques also offer wide possibilities for the ethnomusicologist, who can apply

computerised and synthesised digital recordings in their research. For instance, Simha

Arom adapted a Yamaha synthesiser to simulate a traditional xylophone, recording

the results on a Macintosh SE/30 computer. (Myers, 1992). Also, musicians managed

to correct the tunings to reflect authentic African scales by utilising the computer

(Myers, 1992).

The most frequently used media for digital recording use the PCM (Pulse

Code Modulation) system, including computer, Digital Audio Tape (DAT), compact

disc (CD), Mini Disc (MD) and digital videodisc (DVD). (Refer page 12). According

to Helen Myers (1992), among the DAT tape, videotape and the compact disc, the

latter is said to be the most stable and likely to be the most permanent. In terms of