Those mus. instrs. in which sound is produced by vibrations of a column of air set in motion by the perf.'s blowing. Two main categories are woodwind (not all made of wood) and brass (not all made of brass), e.g. fl., picc., ob., cl., bn., among former; hn., tpt., tb., tuba, among latter. An org. is not a wind instr. in the sense defined here, since the air is mechanically impelled.