"Strawberry Fields Forever" (1967)
The Beatles had lavished more studio time on Lennon's hallucinatory new song than nearly any track to date, recording take after take and eating up 55 hours worth of tape. Ultimately, the decision came down to two distinct versions — a faster one backed by George Martin's bombastic orchestral arrangements, and a gentle, dreamier run-through. Lennon was torn — he liked the quiet beginning of the latter and the raucous end of the former.
"He said, 'Why don't you join the beginning of the first one to the end of the second one?'" Martin explained. "'There are two things against it,' I replied. 'They are in different keys and different tempos.'" While easy to fix today, this was a serious problem in the analog age. But the technologically illiterate Lennon wasn't fazed. "'Well,' he said, 'you can fix it!'"
Armed with little more than two tape machines and a pair of scissors, Martin and his star engineer Geoff Emerick performed a minor mechanical miracle by adjusting the speed on both takes and literally cutting the two tapes together at the 60-second mark. It's become one of the most famous edits in rock history.