Pitch Perfect?

Pitch standards, playback speeds, and metronome marks. In music, time is everything.

On 16 February 1859 the French government passed a law that fixed the frequency of the A note above middle C at 435 Hz. Besides the benefits of uniformity, the new standard sought to end a growing problem: pitch inflation.

Violins, pianos, and other stringed instruments sound livelier when their strings are tightened to raise the pitch. The tightening amplifies the harmonics. High, bright notes sound thrilling to an audience, but they're harder to sing. Pitch inflation was troubling opera singers, whose complaints helped bring about the French law.

Although the French standard didn't catch on everywhere, the idea of a standard did—sort of. In 1995 the International Organization for Standardization chose 440 Hz for its A-note standard, but orchestras around the world have not unanimously adopted it. 

  My guitar tuner can be set to A 440,441, etc etc as desired, not that I'd ever have the desire to meddle.

On 2 March 1959 Miles Davis and his band went into Columbia Records' 30th Street studio in New York City to record the first four tracks of Kind of Blue. They recorded the rest of the album on 22 April. Kind of Blue was an immediate critical and commercial success. It remains the best-selling jazz album of all time.

In 1992 Mark Wilder, senior mastering engineer for Sony Music Studios, undertook a new remastering of the famous album. During the project he discovered an error. The three-channel tape deck used to record the 2 March session had been running slowly. Thus, the first four tracks, which occupied side one of the original vinyl LP, ended up faster and sharper than Davis had intended. Wilder corrected the problem for his remaster.

Not at all uncommon.  I have a number of pieces of music in my collection which seem to be slightly off key to a guitar tuned to A440.  Apparently the speeds on the old tape decks tended to vary somewhat with the amount of tape on the reels.

In 1817, two years after the mechanical metronome had been patented, Beethoven went back to his musical scores and marked the tempi at which each movement should be played. To some conductors, Beethoven's tempi seem too fast, but to others, like Carlos Kleiber shown here, the tempi are exhilarating.