The Mellotron, an electro-mechanical instrument developed in England in 1963, played a crucial role in shaping the distinctive sound of several landmark 1960s rock songs. Functioning like a piano but using recorded tape sounds rather than conventional strings or hammers, the instrument allowed musicians to layer in orchestral and unusual textures that would otherwise have required a full ensemble, helping to expand the sonic possibilities of rock music during the decade.

Three examples illustrate its impact: The Beatles' "Strawberry Fields Forever" (1967) used Mellotron flute sounds, with John Lennon basing the song's title on a real Salvation Army home near his childhood house in Liverpool. The Moody Blues' "Nights in White Satin", written by newcomer Justin Hayward after a girlfriend gave him satin bedsheets, was transformed when keyboardist Mike Pinder added a Mellotron string riff, turning an initially unremarkable track into a favourite. David Bowie's "Space Oddity", recorded in February 1969, also relied on the Mellotron alongside a Stylophone to achieve its distinctive spacey atmosphere, according to producer Gary Dudgeon.