Douglas Harper's Etymology Dictionary
Usage examples of "pitch-pipe".
The clerk drew a pitch-pipe from his bosom, blew the note loud and clear, and the ship's company fearlessly joined their captain in the psalm, a fine deep body of sound.
From somewhere deep in Andy's guts came the wavering honk of a pitch-pipe, followed by a ripple of piano keys.
The reedy note of a pitch-pipe came from somewhere in Andy's diaphragm.
But my ear is far from perfect: a pitch-pipe or a tuning-fork would have infinitely more authority.