Mary,, The annswer is the Dominant 13 (add 11 and 9. For example in the key of G:

GBD are the 1,3,5 of the chord if G is the root (I)

F is the flatted seventh that spells out the dominant seventh.

A is the ninth.

C is the eleventh (4 + (b)7th.

E is the thirteenth.

Hence, within that chord you have GBD (tonic)

NOw here's how it has to work. You have to be in the key of C. G is the dominant chord.

GBD is the V chord. FAC is the IV chord. DFA is the II (minor chord) CEG the I chord is the top part of the sequence (called a chord family). It's the 11th, 13th and the root of the chord found in the next octave.

It can be diagrammed like this.

1,3,5,(b)7,9,11,13 and the repeat of 1 in the next octave.

135 in the key of C if G is the root is the V chord. (GBD)

5,(b)7,9 is the II chord DFA

(b)7,9,11 is the IV chord (FAC)

11,13 and the 1 (root in the next octave) is the I chord (CEG)

The question is how are you going to apply this information?

Dick Grove's jazz arrangement classes use the method of chord families to derive triads (three-note chords) out of one big long chord such as G13 (add 11 and 9).

This is more information than you probably wanted to know but hope it helps.

Frank Hamilton