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Fig. 1 · A9 on the keyboard

piano chord

A9

A1C♯3E5G♭7B9

A dominant seventh carrying a ninth on top.

on guitaron ukulelethe scale

What is true of it

A9 is A, C♯, E, G and B — 1, 3, 5, b7 and 9 counted from A.

On an instrument that cannot reach all 5, the 5 and 1 go first, in that order.

A in other shapes

Aadd9added ninthAmaj9major ninthAm9minor ninthAmajorAmminorAdimdiminished

C9C♯9D♭9D9D♯9E♭9E9F9all 374