piano chord
D♯6
D♯1F𝄪3A♯5B♯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 E♭6 — the same twelve keys on a piano, a different piece of notation.
What is true of it
D♯6 is D♯, F𝄪, A♯ and B♯ — 1, 3, 5 and 6 counted from D♯.
F𝄪 is a double sharp, and it has to be: every letter from D♯ upwards is used once, so the 3 cannot be written any other way.
These are also the notes of Cm7/D♯. 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.