The Beatles are not usually classed among the psychedelic bands of San Francisco's late-1960s Haight-Ashbury scene, having stopped touring before it fully blossomed, yet their music was hugely popular there, and the admiration flowed both ways as the group grew fascinated with acts such as the Grateful Dead and Jefferson Airplane. This mutual influence, according to John Lennon, fed directly into Paul McCartney's concept for the band's next album, shaping one of the most significant creative reinventions in their career.

Lennon recalled that after touring America, McCartney was struck by the trend for long, whimsical band names emerging from the West Coast scene, joking that groups were becoming things like "Fred and His Incredible Shrinking Grateful Airplanes". Rather than mimicking this directly, McCartney used it as partial inspiration, combined with the idea of an old English brass band, to invent an alter ego for the group that would let them experiment freely without risking their existing fanbase. The result was Sgt Pepper's Lonely Hearts Club Band, with the concept taking shape in early 1967 following the band's final paid concert at Candlestick Park in August 1966, which drew a crowd of 25,000.