piano chord
Em7
E1G♭3B5D♭7
Minor triad with a minor seventh. The same four notes as a major sixth chord a third above.
What is true of it
Em7 is E, G, B and D — 1, b3, 5 and b7 counted from E.
These are also the notes of G6/E. 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.