Aaug9

Aaug9 is A, C#, E#, G and B, a augmented ninth. The shape this page opens on is written 323223, lowest string first.

Note by note. A is the root, C# is the major third, E# is the sharp fifth, G is the flat seventh and B is the ninth.

Also written A9#5, A+9 or A9(#5). The same chord either way; which spelling you meet depends on who wrote the chart.

There are 11 common shapes for Aaug9 on the guitar, and 24 derived voicings in 3 families.

One note away. Change a single note of Aaug9 and you have Aalt (with one note moved), Aaug7 (with one note taken away), A9 (with one note moved) or A9b5 (with one note moved).

The common shapes, written lowest string first: 323223, x03423, 543005, 54546x, x05667, 5x5667, xx5667, 9-10-9-10-10-9, x-12-11-12-0-13, x-12-11-12-12-13, 15-14-15-14-14-15.

Under the hand. 2 of the 11 shapes here sit in open position, and the first uses 1 open string with 1 left unplayed. 4 of the 11 need a barre. Together they cover the neck from the 2nd fret to the 15th.

Where it goes. Aaug9 is a dominant with its tension raised, so it still points at D — harder than a plain seventh does, because the altered tones sit a semitone from where they are going.

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. Aaug9 has 5454xx, x0566x, xx7687, x-12-11-12-12-x, x0x021, 5x566x, x-12-x-12-14-13, x0x027.

Rootless. The root left to the bass player. Frees a finger for a tension. Aaug9 has x2302x, xx3423, x4546x, xx5667, x-x-9-10-8-9, x-10-11-10-12-x, x-x-11-12-12-13, x2x021.

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. Aaug9 has x03423, x4300x.

Tensions. A shell of Aaug9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (D#).

What kind of chord this is. Aaug9 is an altered chord — a dominant seventh with its fifth or ninth moved. altered dominant 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.