piano chord
E♭maj7
E♭1G3B♭5D7
Major triad with a major seventh: a half step below the root, an octave up.
Written the other way round it is D♯maj7 — the same twelve keys on a piano, a different piece of notation.
What is true of it
E♭maj7 is E♭, G, B♭ and D — 1, 3, 5 and 7 counted from E♭.
On an instrument that cannot reach all 4, the 5 goes first, in that order.