tetrachord — v/kZ&v"Vd
Tetrachord — A scale series of four sounds, of which the extremes, or first and last, constituted a fourth. These extremes were immutable; the two middle sounds were changeable.
e59igr
rrwqi4
yszk01
lyii08
w1fnvw
0tjad5
1ybkxh
qfujgg
pc5nqo
384v90