pitch

Pitch in the sense of a musical tone's highness or lowness appeared in English by the sixteenth century, but its exact origin is unclear. It may relate to the sense of 'placing' or 'setting' — to pitch a tent, to pitch a camp — through the idea of setting a voice at a particular height. Another theory connects it to the pitched roof, where pitch describes the angle of elevation. A high-pitched voice and a high-pitched roof use the same spatial metaphor: the position on a vertical scale.

The musical definition of pitch — the frequency of a sound wave measured in hertz — was not established until the nineteenth century. Before that, pitch was relative and local. An A in Venice was not the same as an A in Paris. Organ pipes were tuned differently in every church. The lack of standardization made pitch a practical problem for traveling musicians. An instrument tuned to one city's pitch would be out of tune in another.

In 1939, an international conference in London standardized concert pitch at A = 440 Hz. This decision — seemingly technical — ended centuries of local variation. The note A above middle C was now a fixed frequency everywhere in the world. Pitch stopped being a local custom and became a universal standard. The English word of uncertain origin now named one of the most precisely defined quantities in music.

The word's polysemy is remarkable. Pitch is a musical frequency, a tar-like substance (from Latin pix), a sales attempt (from pitching a tent at a fair to sell goods), a throw in baseball, the angle of a propeller blade, and the steepness of a roof. These meanings share no clear etymological connection. English accumulated them from different sources and filed them under the same spelling. The most confusing word in English is also the most fundamental word in music.