piano chord
A♯maj7
A♯1C𝄪3E♯5G𝄪7
Major triad with a major seventh: a half step below the root, an octave up.
Written the other way round it is B♭maj7 — the same twelve keys on a piano, a different piece of notation.
What is true of it
A♯maj7 is A♯, C𝄪, E♯ and G𝄪 — 1, 3, 5 and 7 counted from A♯.
C𝄪 and G𝄪 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.
On an instrument that cannot reach all 4, the 5 goes first, in that order.