Studios Two and Three, EMI Studios, Abbey Road
Producer: George Martin
Engineers: Ken Scott, Ken Townsend
The Beatles added overdubs to three The Beatles (White Album) songs, and mixes of two others were made, during two separate sessions on this date.
George Harrison’s ‘Piggies’ was the first to receive an overdub. A string arrangement by George Martin was added to take 12, featuring eight players: Henry Datyner, Eric Bowie, Norman Lederman, and Ronald Thomas on violin; John Underwood and Keith Cummings on viola; and Eldon Fox and Reginald Kilbey on cello.
The same session musicians then added a string part to ‘Glass Onion’. Stereo mixes of ‘Glass Onion’, ‘Rocky Raccoon’ and ‘Long, Long, Long’ were then made, along with a mono mix of ‘Glass Onion’.
The session took place from 7pm-7.15am in Abbey Road’s Studio Two. In Studio Three, meanwhile, Paul McCartney completed the recording of ‘Why Don’t We Do It In The Road?’ with engineer Ken Townsend.
The basic track for ‘Why Don’t We Do It In The Road’ had been taped on the previous day, with McCartney working alone. This time, however, he enlisted the help of Ringo Starr.
Recording on four-track tape, the pair added bass guitar and drums onto track tree. McCartney then re-recorded his lead vocals onto track one, erasing his original acoustic guitar part in the process, although percussion slaps on the instrument were retained.
Handclaps were then added to track two in the introduction, and track four was filled with a second vocal part. A reduction mix, numbered take six, was then made, onto which McCartney finally overdubbed an electric guitar part.
On this day, Jeff Lynne (then of ‘The Idle Race’, later ‘The Move’, then ‘ELO) was at Abbey Road to witness the strings’ overdub on ‘Glass Onion’ and the recording of ‘Why Don’t We Do It In The Road?’.
Source: https://www.rollingstone.com/music/music-news/the-second-coming-of-jeff-lynne-228853/
Jeff Lynne must’ve been so lucky to witness this and here’s some trivia about The Move and ELO: the original idea was to pick up where The Beatles left off with “I am the Walrus” and the original idea was to have both The Move and ELO coexist in parallel, but it never happened in the end, since The Move became ELO after a final Roy Wood-penned single “California Man”.
Paul’s original acoustic guitar part was still retained in the final mix of WDWDIITR, not just the percussive slaps. You can hear his guitar strums at the 0:37 mark.
The reason why he didn’t enlist John or George’s assistance was not because he didn’t want their input, but because the two guitarists were occupied with supervising string overdubs.
In “Beatles Monthly”, Mal Evans incorrectly stated that Paul played everything himself on WDWDIITR, but in truth, Ringo was involved as well and he played the drums.