triads and inversions.docx

7/27/2019 Triads and Inversions.docx

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Lesson Three

Triads and Inversions

To be able to harmonise to a melody we are given, we need to be able to understand

the chords given to us.

Three note chords are called triads, and are identified by the scale degree of their

lowest note, using Roman numerals.

(minor chords are in lower case numerals, major chords in upper case!)

If we add another step to a triad, we get a 7th

chord, so called because the interval

between the root and this note is a 7th

. In the exam you may be asked to identify II7

and V7 add these on the stave above where you think they should go, and relabel

the chords.

The note after which a chord named is called its root and the other notes in the

chord are named accordingly to the interval.

Label this chord with root, 3rd and 5th

, and draw and

label the 7th

note.

We can use any of these notes as the lowest note of the chord, by adding a lower-

case letter to the chords Roman numeral.

Root = a

3rd= b5

th= c

7th

= d

Label the chord above with its letter name also.

If the root is the lowest note, we say the chord is in root position really youshould put the letter a after the chord e.g. Iva, but it is always assumed that a

chord is in root position if there is no letter.

If the third is the lowest note, the chord is in first inversion and we add theletter b e.g. IVb


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Lesson Three

If the fifth is the lowest note, the chord is in second inversion and we add theletter c e.g. Vc

If the chord has a seventh and if this is the lowest note, the chord is in thirdinversion and we add the letter d e.g. VIId

The notes of a chord may appear in any order and will usually be spread over more

than one stave. Some notes may be doubled, the fifth may be left out, and

sometimes each of the notes may be sounded separately to form a broken chord.

Task:

Step 1: Identify the key this music is in

Step 2: Identify each chord (with its Roman Numeral)

Step 3: Identify the inversion and label


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Lesson Three

How to identify chords

Step 1: Work out the key of the passage and make a chord chart for the key:

7th

(d) D G

5th

(c) A B C# D E F# G

3rd

(b) F# G A B C# D E

root D E F# G A B C#

D major I II(7) III IV V(7) VI VII

Step 2: Write down the names of the notes in the chord you want to identify,

ignoring doubles and writing the lowest note of the chord at the bottom

e.g. chord 1: A chord 2: D

D# B

F E

G

Step 3: Match the notes you have listed with a chord in your chart and write its

Roman numeral.

e.g. Chord 1: I chord 2: II7

Step 4: Check the chords lowest note against the inversion letters in your chart, and

then add the correct letter after the Roman numeral

e.g. Chord 1: Ib chord 2: II7b

Task: Complete for the other two chords on this extract.


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Lesson Three

You may be also be asked to identify the diminished 7th

. The interval between ever

note is a minor 3rd

.

Chords VII7 in a minor key is a diminished 7th

, but if it is in a major key, at least one

of its notes is chromatic (not part of the key).

Exercises

Label the chords using Roman numerals and inversions below each chord.

Identify the chords that are bracketed with a letter over e.g. A and B in this exercise


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Lesson Three

Figured Bass

Figured bass is a method for indicating chords, used widely in the 17th

and 18th

centuries you will be expected to understand this at A2 level, and makes moresense to teach as part of AS during your understanding of inversions!

The figures refer to intervals above the given bass note in accordance with the key

signature.

5-3 means root position. So the B is the root note, and

you would write the 3rd

and the 5th

note above, but

where you position them in the stave is up to you.

In these examples, the root note has been doubled. You can also double the 5th

if

you wish, but dont double the 3rd

.

Sometimes you wont see a figure underneath a note that means its 5-3 its just a

common root chord.

A 6-3 chord is a first inversion chord. That means you

would need to write the notes a 3rd

above and a 6th

above this note e.g. an E and an A. (You will then notice

that its an A chord in first inversion!) You can double

any of the notes on a 6-3 chord.

As a 6-3 chord is quite common too, you might see it

only written as a 6. It still means 1st

inversion!

Hint with figured bass: work out the inversions and letter names that you need toharmonise with first then you will realise which inversion it is.


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Lesson Three

A 6-4 chord is second inversion. You would need to write the

notes a 4th

and a 6th

higher than the bass note. You should

always double the bass note with a 6/4.

If you see a sharp, you would need to sharpen that

note. For this root position figured bass, you need to

sharpen the 3rd

.

For this second inversion figured bass, you need to

sharpen the 6th

interval.

Exercise: Work out this figured bass together

1. No numbers = root position2. No numbers = root position + #3. Line hold previous chord4. First inversion5. Second inversion


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Lesson Three

Possible Solution:

The important point of figured bass isnt just to work out the chords! You need to

have a nice melody running through the soprano line, and make sure the alto andtenor lines dont jump all over the place they should normally move by step.

Main rules of figured bass:

1. No consecutive 5ths or 8ves2. Soprano line to have a nice melody, and alto and tenor lines to fill out the

harmony. No wide leaps or difficult intervals

3. Always check you have doubled the right note normally the root of 5th.4. Dont let parts overlap

Steps to complete a figured bass:

1. Work out the key of the piece2. Write down the notes you need by name3. Write the whole soprano line4. Fill in the alto and tenor parts, chord by chord5. Check for errors and rewrite where necessary

Homework realize this figured bass.

triads and inversions.docx

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