Although a guitarist and, from 1966, an aspiring sitarist under Indian musician Ravi Shankar, George Harrison turned to keyboard instruments as a tool for songwriting in 1967. These instruments included Hammond organ on some of his songs with the Beatles, and Mellotron on several of the Western selections on his debut solo album, the Wonderwall Music film soundtrack. Described by producer George Martin as the most dedicated of the Beatles in finding and creating new sounds for the band's studio recordings, Harrison became intrigued by the potential of the Moog synthesizer while in Los Angeles in late 1968. He was introduced to the instrument by Bernie Krause, who, along with his Beaver & Krause partner Paul Beaver, was the Moog company's sales representative for the US West Coast.
An off-shoot of the Beatles' Apple record label, Zapple Records was intended as an outlet for avant-garde musical works and spoken-word albums. The music on Electronic Sound, consisting of two extended instrumental pieces – "Under the Mersey Wall" and "No Time or Space" – was performed on a Moog 3 modular system. Harrison bought the system from the Moog company through Krause, and later had it set up at EMI Studios in London for the Beatles to use on their recordings.
In author Alan Clayson's view, the album was Harrison's "gesture of artistic solidarity" towards John Lennon and Yoko Ono, whose experimental collaborations, having first appeared on the Beatles' 1968 track "Revolution 9", made up Zapple's other inaugural album, Life with the Lions. In a 1987 interview, Harrison said that Electronic Sound, like the Lennon–Ono album, was an example of Zapple's ethos of "let[ting] serendipity take hold" rather than a formal creative work.
(en.wikipedia.org/wiki/Electronic_Sound)