Bbaug9

Bbaug9 is Bb, D, F#, Ab and C, a augmented ninth. The shape this page opens on is written x10112, lowest string first.

Note by note. Bb is the root, D is the major third, F# is the sharp fifth, Ab is the flat seventh and C is the ninth.

Also written Bb9#5, Bb+9 or Bb9(#5). The same chord either way; which spelling you meet depends on who wrote the chart.

There are 7 common shapes for Bbaug9 on the guitar, and 23 derived voicings in 3 families.

One note away. Change a single note of Bbaug9 and you have Bbalt (with one note moved), Bbaug7 (with one note taken away), Bb9 (with one note moved) or Bb9b5 (with one note moved).

The common shapes, written lowest string first: x10112, 434334, 65657x, 6x6778, xx6778, 10-11-10-11-11-10, x-13-12-13-13-14.

Under the hand. 1 of the 7 shapes here sits in open position, and the first uses 1 open string with 1 left unplayed. 4 of the 7 need a barre. Together they cover the neck from the 1st fret to the 14th.

Where it goes. Bbaug9 is a dominant with its tension raised, so it still points at Eb — 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. Bbaug9 has x1011x, 6565xx, xx8798, x-13-12-13-13-x, x1x132, 6x677x, x-13-x-13-15-14, 6x011x.

Rootless. The root left to the bass player. Frees a finger for a tension. Bbaug9 has xx0112, xx4534, x5657x, xx6778, x-x-10-11-9-10, x-11-12-11-13-x, x-x-12-13-13-14, x3413x.

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. Bbaug9 has x56570.

Tensions. A shell of Bbaug9, root, third and seventh, leaves a string free, and the tones that belong over it are the #11 (E).

What kind of chord this is. Bbaug9 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.