Abbey Road, Let It Be and break-up

Although Let It Be was the band's final album release, most of the material on it was recorded before Abbey Road. The project's impetus came from an idea Martin attributes to McCartney, who suggested they "record an album of new material and rehearse it, then perform it before a live audience for the very first time – on record and on film."^[206] Originally intended for a one-hour television programme called "Beatles at Work", much of the album's content came from the extensive studio rehearsals filmed by director Michael Lindsay-Hogg.^[206][207] Uncharacteristically, work began at Twickenham Film Studios in January 1969, not EMI or Apple.^[208] Martin said the project, was "not at all a happy recording experience. It was a time when relations between the Beatles were at their lowest".^[206] Lennon described the largely impromptu sessions as, "hell ... the most miserable ... on Earth", and Harrison, "the low of all-time".^[209] Aggravated by both McCartney and Lennon, Harrison walked out for five days. Upon returning, he threatened to leave the band unless they "abandon all talk of live performance" and instead focus on finishing a new album, initially titled Get Back, using songs recorded for the TV special.^[207] He also demanded they cease work at Twickenham and instead commence at a newly-finished Apple Studios, the band agreed, and at this point the idea came about to salvage the footage shot for the TV production for use in a feature film.^[210]
In an effort to alleviate tensions within the band and improve the quality of their live sound, Harrison invited keyboardist Billy Preston to participate in the last nine days of sessions,^[211] and he received "label billing" on the "Get Back" single—the only musician ever to receive that acknowledgment on an official Beatles' release.^[212] At the conclusion of the rehearsals, the band could not agree on a location to film a concert, rejecting several ideas, including; a boat at sea, a lunatic asylum, the Tunisian desert, and the Colosseum.^[206] Ultimately, what would be their final live performance was filmed on the rooftop of the Apple Corps building at 3 Savile Row, London, on 30 January 1969.^[213] Five weeks later, engineer Glyn Johns, whom Lewisohn describes as Get Back's "uncredited producer" began work assembling an album, having been given "free rein" while the band "all but washed their hands of the entire project."