Learning jazz piano chords is taking chords to a new level. Jazz chords move beyond the major, minor and 7th chords. They have a few more variations.
This page will explain the basics of some of the more complicated chords and how to play them. (For the basic kinds of chords go to the reading chords page.)
To understand jazz chords, you need to understand how a 7th chord
works. In a 7th chord, you lower the 7th note of a major
scale by one
semi-tone. For example B becomes Bb. The C7 chord has C E G Bb.
For any chord with a number higher than 7 (like 9, 11, or 13), you must include the lowered 7th note. That base of that chord is that 7th chord.
If the chord has the word "add" then you don't add the 7th note of the scale. Just play the chord and add that numbered note of the scale.
For example, Cadd9 means to play C E G D.
C9 - a 9th Chord
This chord includes the 7th chord. To play this chord you use the 1st, 3rd, 5th, lowered 7th, and 9th notes of the scale. To figure them out just keep counting up from the root note.
With this chord, you will maybe not actually play the 5th note. There gets to be too many notes to play.
C9 = C E (G) Bb D.
C11 - an 11th Chord
The 11th chord chord adds one more note onto the 9th chord. You may not play the 5th and 9th notes. Play the 1st, 3rd, b7th, and 11th notes.
C11 = C E (G) Bb (D) F
Either of these chords can be made into minor 9th or 11th chords. In either case you lower 3rd note.
Cdim - a Diminished Chord
In a diminished chord, you must lower the 3rd and 5th notes of the major scale. Play the 1st, lowered 3rd, and lowered 5th notes. For example, Cdim becomes C Eb Gb.
Cdim7 - a Diminished 7th Chord
Play the diminished chord and then add the 7th note by lowering it by a whole tone (2 semi-tones). This means B becomes Bbb. Or C# becomes Cb.
Cdim7 = C Eb Gb Bbb.
Caug - an Augmented Chord
An augmented chord raises the 5th note of the scale by one semi-tone. The chord is the 1st, 3rd, and raised 5th notes of the major scale. Caug (or Cx) is C E G#.
In jazz piano chords you may also see a flat (b) or a sharp (#) in front of a number or letter. For example C7b5 or C7#5. This tells you what note of the chord to raise or lower out of the ordinary.
In our example of C7b5, you have to lower the 5th note of the scale - changing it from G to Gb. If it was raised do the opposite, change G to G#.
There are many more jazz piano chords. To continue to learn them I would recommend choosing a lead sheet to practice from. Learn the specific chords there and once you're comfortable move on to another one.
Here's a great video to learn more from: