The examples below show the dominant seventh chord with added 9, 9, 9 (or 10), 11 (or 5), 13, and 13 (or 5).

Major

Note that the 6, 6/9, maj7, and maj9 are alternately used as tonics.

The most effective voicings of these chords are shown below. Memorize the structures of the above chords using numbers from the bass to the soprano:

	9th lead	drop 2	5th lead*	drop 2*	9 or 9 lead	11 lead	13 lead*
RH	9 7 5 3	9 5 3	5 3 9 7	5 9 7	9    9 7     7 5     5 3     3	11 3 9 7	13    13   5 3        3       3 9        9       9 7        7       7
LH	1	7 1	1	3 1	1     1	1	1        1        1

*When the 6^th is an extension of the dominant seventh chord, it is labeled as the 13^th to distinguish it from the tonic 6 or 6/9 chord.

Minor

Note that the m6, min6/9, min-maj7, and the min9-maj7 are alternately used as tonics.

Note that the C7(9 13) chord is enharmonically equivalent to the C7+(9). Jazz musicians alternately use C7+ or C7+(9) in minor keys because of the simpler notation.

summary of extensions of the Dominant seventh Chord

Alterations related to the 5^th and 9^th of the dominant 9^th chord include:  11,  5,  5,  5,  13,  13,  9,  9,  and  9.