Jazz comping for non pianists

As a basically self taught musician, one of the areas I always felt underpowered was playing the piano. When I started to seriously investigate jazz, my lack of ability on keys made understanding harmony and hearing chord progressions much more difficult. Gilad Atzmon first introduced me to a remarkably simple system of playing chords on the piano that transformed my abilities in this area. It gave me a way to play through any jazz standard on the piano and hear how the underlying harmony worked. I would like to pass on this valuable system to all you horn players that have shied away from the piano. This system will not make you Bill Evans, but will give you a way of accompanying yourself singing, or another musician playing, with a skeleton version of a songs harmony and voice leading.

Background :

Jazz chords ( in their most basic form ) are 4 note chords derived from the major scale. For example, in the key of C major the chords are as follows :

1	C	C Major 7th	CMaj7	C E G B	1 3 5 7
2	D	D minor 7th	Dm7	D F A C	2 4 6 8
3	E	E minor 7th	Em7	E G B D	3 5 7 9
	F	F Major 7th	FMaj7	F A C E	4 6 8 10
5	G	G dominant 7th	G7	G B D F	5 7 9 11
6	A	A minor 7th	Am7	A C E G	6 8 10 12
7	B	B half diminished	Bm7b5	B D F A	7 9 11 13

In all keys there are 2 major seventh chords ( on the root and 4th ), 3 minor chords ( on the second, third and sixth ), 1 dominant seventh chord ( on the fifth ) and 1 half diminished seventh chord ( on the seventh ). In C this gives Cmaj7 and Fmaj7 on 1 and 4. Dm7, Em7 and Am7 on 2, 3 and 6. G7 on 5 and Bdim7 on 7.

Note that there is only one dominant chord in each key. You can use this to identify what key you are in at any given time ( jazz tunes and standards from the 30', 40's and 50's often change key a number of times ).

G7 indicates the key of C.
A7 the key of D.
Ab7 the key of Db.


The System :

When confronted by a chord sequence simply play the root of the chord with your left hand and play the 3rd and the 7th of the chord with your right. That's it. Play the root below middle C. Voice the right hand notes in the centre of the keyboard in whichever inversion is most comfortable and/or sounds the best.

For example :

All Of Me in C.

C / / / C / / / E7 / / / E7 / / / A7 / / / A7 / / / A- / / / D7 / / /
E7 / / / E7 / / / A- / / / A- / / / D7 / / / D7 / / / D- / / / G7 / / /
C / / / C / / / E7 / / / E7 / / / A7 / / / A7 / / / A- / / / D7 / / /
D- / / / G7 / / / E- / / / A7 / / / D- / / / G7 / / / C / / / C / / /

First play through the tune playing only the bass notes at the start of each bar. Sing the melody.
When you are comfortable doing this add the third and the seventh from each chord.

Chord	Root	Third	Seventh
C	C	E	B
E7	E	G#	D
A7	A	C#	G
D7	D	F#	C
Dm7	D	F	C
G7	G	B	F
Am7	A	C	G
Em7	E	G	D

Working out seventh of each chord :

On minor and dominant chords the seventh is a tone ( whole step : 2 semitones ) down from the root. On major chords the seventh is a semitone down from the root.

For simplicities sake I would suggest treating all Major chords ( including 6 and 6/9 ) as Major 7th whether indicated or not. 9 chords as 7. Diminished chords can be played as minor. This means only 3 qualities of chord need be memorised. Alterations of chords such as b5, #5, b9, b11, #11 and b13 can be ignored .