pitch-pipe (n.)

1520s, "something that is thrust in or fixed or pierced," from pitch (v.1). Sense of "slope, degree, inclination" is from 1540s; from 1550s as "highest point or reach;" from 1620s as "height" in general. Meaning "height of an arched roof above the floor" is by 1610s.

Meaning "a throw, a toss, an act of throwing" is attested by 1833. Meaning "act of plunging headfirst" is from 1762. The musical sense of "characteristic of a sound or tone that depends upon relative rapidity of vibration" is from 1590s, also "particular tonal standard." See pitch (v.1) for sense evolutions, but the connection of many of these is obscure.

Some noun senses are from the older sense of pitch as "to thrust in, drive (a stake)." Thus, in cricket, "place where the wickets are pitched" (1871).

Sales pitch in the modern commercial advertising sense is from 1943, American English; pitch in the sense of "tedious or inflated sales talk" is attested by 1876, perhaps ultimately from the baseball sense. Pitch also was "place on which to pitch or set up a booth for sale or exhibition" (by 1851).

Old English pipe "simple tubular musical wind instrument," also "tube for conveying water," from Vulgar Latin *pipa "a pipe, tube-shaped musical instrument" (source also of Italian pipa, French pipe, Old Frisian pipe, German Pfeife, Danish pibe, Swedish pipa, Dutch pijp), a back-formation from Latin pipare "to chirp or peep," of imitative origin.

All the tubular senses ultimately derive from the meaning "small reed, whistle." From late 14c. as "a tube or duct of the body." From mid-15c. as "one of the tubes from which the tones of an organ are produced." Meaning "narrow tubular device for smoking" is recorded by 1590s. As "the sound of the voice," 1570s.

Pipe-bomb, "home-made bomb contained in a metal pipe," is attested from 1960. Pipe-cleaner, "piece of wire coated with tufted material," is recorded from 1863. Pipe-clay "white clay suitable for making smoking pipes" is attested by 1777.