piano chord
A13
A1C♯3E5G♭7B9F♯13
Seven notes in theory and four or five in anyone’s hands: root, third, seventh and thirteenth carry it.
What is true of it
A13 is A, C♯, E, G, B and F♯ — 1, 3, 5, b7, 9 and 13 counted from A.
On an instrument that cannot reach all 6, the 5, 9 and 1 go first, in that order.