G9

G9 is G, B, D, F and A, a dominant ninth. The shape this page opens on is written 300001, lowest string first.

Note by note. G is the root, B is the major third, D is the fifth, F is the flat seventh and A is the ninth.

Also written Gdom9 or G dominant 9. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 10 common shapes for G9 on the guitar, and 50 derived voicings in 5 families.

One note away. Change a single note of G9 and you have Gmaj9 (with one note moved), Gm9 (with one note moved), Gadd9 (with one note taken away), G69 (with one note moved), G7 (with one note taken away) or G9b5 (with one note moved).

In which keys. Every note of G9 belongs to C major (the V) and A minor (the ♭VII).

The common shapes, written lowest string first: 300001, 3232xx, 353235, 353435, xx5465, 7x5765, x-10-9-10-10-10, x-12-12-12-12-13, 15-12-12-14-12-13, 15-14-15-14-15-x.

Under the hand. 1 of the 10 shapes here sits in open position, and the first uses 4 open strings. 6 of the 10 need a barre. Together they cover the neck from the 1st fret to the 15th.

Where it goes. G9 is the V of C, and that is where it goes if it goes anywhere: the third and the flat seventh are a tritone apart, and both resolve by a semitone into C.

Shell. Root, third and seventh: the guide tones fix the quality, so the fifth is dropped. That is what leaves a string free, so pick a tension to put on top. G9 has 3232xx, xx5465, x-10-9-10-10-x, 15-14-15-14-x-x.

Drop 2. A close-position chord with the second voice from the top lowered an octave. Sits on four adjacent strings. G9 has 3232xx, xx3203, x0300x, xx5465, x-10-9-10-10-x, 15-14-15-14-x-x, x2526x, 5854xx.

Drop 3. The third voice from the top lowered an octave. The dropped voice becomes the bass, which is why a string is skipped. G9 has x0x001, 3x320x, x2x263, 5x546x, x8x485, x-10-x-10-10-7, 7-x-7-10-8-x, 13-x-9-12-10-x.

Rootless. The root left to the bass player. Frees a finger for a tension. G9 has xx0201, x2323x, xx3435, xx7767, x-x-9-10-10-10, x-12-12-10-12-x, x-x-12-14-12-13, x-14-15-14-15-x.

Open string. An open string left ringing against a fretted grip. Because it costs no finger, it sounds a note the closed shape has none left for -- a tension on top, or a pedal root underneath. Either a familiar grip with open strings added, or a shape so sparse the open strings carry the chord. These belong to their key rather than to a shape, so D, A, G and E have many and Eb a handful. G9 has 323200, x23230, 5x5460, x57460, x03000, x00067.

Tensions. A shell of G9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (C#), the b13 (Eb) and the 13 (E).

What kind of chord this is. G9 is a dominant chord — root, major third, fifth, minor seventh. dominant seventh chords on every root, and what they are for.

The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.