guitar chord
A♯6
A major triad with a sixth added. The same four notes as a minor seventh chord a third below.
Written the other way round it is B♭6 — the same twelve keys on a piano, a different piece of notation.
Every fingering that fits a hand
x10031
open
x10033
open · no 5
650063
moderate
x1003x
open · no 5
x13031
moderate
What is true of it
A♯6 is A♯, C𝄪, E♯ and F𝄪 — 1, 3, 5 and 6 counted from A♯.
C𝄪 and F𝄪 are double sharps, and they have to be: every letter from A♯ upwards is used once, so the 3 cannot be written any other way.
These are also the notes of Gm7/A♯. Which name is right depends on what is underneath and what came before — the notes alone do not decide.
On an instrument that cannot reach all 4, the 5 goes first, in that order.
The easiest of the 5 fingerings below is x10031: 3 fingers, held at the 1st fret.
3 of them use open strings, which is what makes a shape quiet to change to.
1 string stays silent.
Where its notes are on the neck
The brass dots are A♯, the root. Everything else is a chord tone with its degree printed in it.
With a different note underneath
A♯6/C𝄪
xx0333
A♯6/E♯
1100xx
A♯6/F𝄪
310031
An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.