The Beatles’ song “A Hard Day’s Night” opens with a single, resounding chord. In Mark Lewisohn’s 1988 book The Beatles Recording Sessions, George Martin, the Beatles producer, explained the chord’s origin: “We knew it would open both the film and the soundtrack LP, so we wanted a particularly strong and effective beginning. The strident guitar chord was the perfect launch.”
Remarkably, given the Beatles’ fame and the work of Lewisohn and other enthusiasts, the actual notes that make up the iconic chord were in dispute. For a taste of the attention the chord has attracted, here’s a paragraph from the chord’s Wikipedia entry:
According to Walter Everett, the opening chord has an introductory dominant function because McCartney plays D in the bass; Harrison and Martin play F A C G in twelve string guitar and piano, over the bass D, giving the chord a mixture-coloured neighbour, F; two diatonic neighbours, A and C; plus an anticipation of the tonic, G—the major subtonic as played on guitar being a borrowed chord commonly used by the Beatles.
The chord’s composition was purportedly resolved in 2004 by Jason Brown of Canada’s Dalhousie University in Halifax, Nova Scotia. His Fourier analysis of the elusive chord revealed an extra ingredient that Everett had missed: John Lennon’s guitar.
Fourier-analyzing the Beatles might seem like a misuse of science. If Albert Einstein had lived to hear the Beatles, he’d have probably agreed. “It would be possible to describe everything scientifically,” he once said, “but it would make no sense; it would be without meaning, as if you described a Beethoven symphony as a variation of wave pressure.”
I disagree with Einstein, as, presumably, do the authors of the many papers in the Journal of the Acoustical Society of America and other journals that are devoted to understanding music’s nature, production, and perception. Those papers enrich, rather than diminish, our appreciation of music. You can find some of them in Physics Today‘s Physics Update department. Among the topics we’ve covered are Balinese gongs, the perception of minor and major keys, newborn babies’ sense of rhythm, and the musical columns of the Vitthala Temple.
A final note: Beethoven’s Piano Concerto No. 5 in E-flat major opens in the same way as “A Hard Day’s Night”—with a single chord.