1520s, "something that is pitched," from pitch, v.1. Meaning "act of throwing" is attested from 1833. Meaning "act of plunging headfirst" is from 1762; sense of "slope, degree, inclination" is from 1540s; musical sense is from 1590s; but the connection of these is obscure. Sales pitch in the modern commercial advertising sense is from 1943, American English, perhaps from the baseball sense.

"resinous substance, wood tar," late 12c., pich, from Old English pic "pitch," from a Germanic borrowing (Old Saxon and Old Frisian pik, Middle Dutch pik, Dutch pek, Old High German pek, German Pech, Old Norse bik) of Latin pix (genitive picis) "pitch," which according to Watkins is from a PIE root *pik- "pitch" (cognates: Greek pissa, Lithuanian pikis, Old Church Slavonic piklu "pitch"), but according to Pokorny this is from the same PIE root as pine, n.. The English word was applied to pine resins from late 14c. Pitch-black is attested from 1590s; pitch-dark from 1680s.

c.1200, "to thrust in, fasten, settle," probably from an unrecorded Old English *piccean, related to prick, v.. The original past tense was pight. Sense of "set upright," as in pitch a tent (late 13c.), is from notion of "driving in" the pegs. Meaning to incline forward and downward" is from 1510s. Meaning "throw (a ball)" evolved late 14c. from that of "hit the mark." Musical sense is from 1670s. Of ships, "to plunge" in the waves, 1620s. To pitch in "work vigorously" is from 1847, perhaps from farm labor. Related: Pitched; pitching.

"to cover with pitch," Old English pician, from the source of pitch, n.2.