capture his acoustic guitar. Overdubs Take 16 of "My Sweet Lord" was selected for overdubs. From late July onwards, Harrison and Peter Frampton added further acoustic guitars to the song and to other tracks from the album. The chorus vocals were all sung by Harrison and credited to "the George O'Hara-Smith Singers". These contributions, together with Harrison's slide guitar parts and Barham's orchestral arrangement, were overdubbed during the next two months, partly at Trident Studios in central London with engineer Ken Scott. Harrison experimented with several harmony ideas in his guitar parts, having first applied himself to mastering slide during the 1969 Delaney & Bonnie tour. Scott had to extend the original track, repeating a portion of the final section, to allow for the closing prayer and fadeout. The session for Barham's string arrangement took place on 18 September, involving 22 orchestral musicians. Arrangement Harrison biographer Simon Leng describes the completed recording as a "painstakingly crafted tableau" of sound, beginning with a bank of "chiming" acoustic guitars and the "flourish" of zither strings that introduces Harrison's slide-guitar motif. At close to the two-minute mark, after the tension-building bridge, a subtle two-semitone shift in key (from E major to the rarely used key of F major, via a C dominant seventh chord) signals the song's release from its extended introduction. This higher register is then complemented by Harrison's "increasingly impassioned" vocal, according to Inglis, and the subsequent "timely reappearance" of his twin slide guitars, before the backing vocals switch to the Sanskrit mantra and prayer. Leng comments on the Indian music aspects of the arrangement, in the "swarmandal-like" zithers, representing the sympathetic strings of a sitar, and the slide guitars' evocation of sarangi, dilruba and other string instruments. In an interview for Martin Scorsese's 2011 documentary George Harrison: Living in the Material World, Spector recalls that he liked the results so much, he insisted that "My Sweet Lord" be the lead single from the album. This rock version of the song was markedly different from the "Oh Happy Day"-inspired gospel arrangement in musical and structural terms, aligning Harrison's composition with pop music conventions, but also drawing out the similarities of its melody line with that of the Chiffons' 1963 hit "He's So Fine". Beatles historian Bruce Spizer writes that this was due to Harrison being "so focused on the feel of his record", while Record Collector editor Peter Doggett wrote in