1. "Get Back"
The first draft of "Get Back" included the line "Don't dig no Pakistani taking all the people's jobs," but the line was cut when the band realized that the lyric, intended to be an ironic comment on right-wing groups attacking Pakistani immigrants, would be interpreted as racist. They were right about this: Years later, The Sun found a copy of the first draft and accused the band of xenophobia.
2. "Can't Buy Me Love"
The band's regular sound engineer Norman Smith played all the hi-hat parts in "Can't Buy Me Love" after discovering that the tape with the percussion parts recorded in Paris had a ripple in it when it arrived at Abbey Road, which lost the treble in Ringo Starr's performance. Smith recorded new parts himself, but The Beatles never knew about it.
3. "Martha My Dear"
Paul McCartney wrote "Martha My Dear" about his beloved 3-year-old Old English sheepdog, though it's more likely the romantic lyrics were really about his eventual wife Linda Eastman, who he met just before the song was written.
4. "I Am the Walrus"
The "egg man" in "I Am the Walrus" was a reference to John Lennon's friend Eric Burdon of The Animals. He gave him that nickname after Burdon told him a story about a sexual encounter he had with a Jamaican woman who cracked an egg on his bare stomach and licked the yolk off his body.
5. "Twist and Shout"
Nearly all of Please Please Me was recorded live to tape in a single day — Feb. 11, 1963 — and "Twist and Shout" was the final song to be tracked. The song was saved for last because John Lennon was feeling very ill, and George Martin wanted to preserve his voice through the day. By the time they recorded the song, Lennon had a very sore throat but sucked on a few Zubes cough drops, gargled some milk, and took off his shirt before launching into one of the finest — and raspiest — performances of his career. "My voice wasn't the same for a long time after," he said in 1976. "Every time I swallowed it was like sandpaper."
6. "When I'm Sixty-Four"
Paul wrote "When I'm Sixty-Four" on his father's piano when he was 16, years before co-founding The Beatles. The song was played often during the band's residency at the Cavern Club, usually with just Paul on piano to kill time if one of the amps broke down.
7. "Day Tripper"
German radio programmers were reluctant to play "Day Tripper" on the air because the word "tripper" is German slang for gonorrhea.
8. "Come Together"
"Come Together" was conceived as a rally song for LSD guru Timothy Leary's campaign to become the governor of California and unseat the Republican incumbent Ronald Reagan in 1969. Leary's campaign slogan was "come together, join the party," with the word "party" intended as a reference to drug culture. Leary's campaign came to an end when he was incarcerated for drug possession, which freed Lennon up to develop it as a Beatles song instead. Leary later attacked Lennon for "stealing" the idea, but Lennon maintained that he owed him nothing.
9. "I Saw Her Standing There"
Paul McCartney says in the book Paul McCartney: Many Years From Now that the bass line from "I Saw Her Standing There" was lifted from Chuck Berry's "I'm Talking About You." "I played exactly the same notes as he'd did and it fitted our number perfectly," he said. "Even now when I tell people about it, I find few of them believe me. Therefore I maintain that a bass riff doesn't have to be original."
10. "With a Little Help from My Friends"
The original line in "With a Little Help from My Friends" was "What would you do if I sang out of tune / Would you stand up and throw tomatoes at me?" but Ringo made them change it, presumably because he didn't want anyone to actually throw tomatoes at him if they were to perform it in concert.
11. "Savoy Truffle"
George Harrison wrote "Savoy Truffle" as a joke about his best friend Eric Clapton's obsession with chocolate and candy. Clapton had a lot of dental problems as a result of his sweet tooth, hence the line "You'll have to have them all pulled out after the Savoy Truffle."
12. "Penny Lane"
"Penny Lane" is named after a street in Liverpool, which in turn was named after James Penny, a wealthy 18th-century slave trader and vocal opponent to abolitionist legislation. This wasn't widely known at the time the song was written, so it's just an unfortunate coincidence.
13. "Helter Skelter"
Paul was inspired to write "Helter Skelter" after reading a Pete Townshend quote in Melody Maker in which he boasted that "I Can See for Miles" was the loudest, rawest, more uncompromising song they had ever recorded. He went out of his way to go even further, without having even heard The Who song.
14. "Yellow Submarine"
Donovan, the singer-songwriter of '60s hits like "Season of the Witch" and "Mellow Yellow," contributed the line "Sky of blue, and sea of green, in our yellow submarine" to "Yellow Submarine." Ringo also accidentally sang, "Every one of us has all we need" instead of "Every one of us has all he needs," and Paul embraced the error, officially changing it to Ringo's slip-up version.
15. "Octopus's Garden"
Ringo wrote "Octopus's Garden" after being served octopus instead of fish and chips while on vacation. When he asked about the dish, which he'd never eaten before, the captain told him about the habits of the octopus and their custom of accumulating objects and shellfish in a cave like a small garden.
16. "Doctor Robert"
According to Paul, John wrote "Doctor Robert" about Dr. Robert Freeman, the owner of a clinic in New York who prescribed a cocktail of vitamin B12 and huge doses of amphetamines to celebrities in the city. Remember that one episode of Mad Men? Just like that.
17. "Oh! Darling"
"Oh! Darling" was the final song John Lennon recorded with The Beatles. The last thing he tracked with the band was backing vocals for this song on Aug. 11, 1969.
18. "Hey Bulldog"
The video for "Lady Madonna" was actually made from footage of the band recording "Hey Bulldog" in the studio. Neil Aspinall had the video recut to "Hey Bulldog" many years later, and it's the only clip that exists of the band recording a song in Studio Three at Abbey Road. Incidentally, the session for "Hey Bulldog" is the final session in which all four Beatles were together in the studio. Afterward, Yoko Ono was a regular in the studio.
19. "Dig a Pony"
The line "I pick a moondog" in "Dig a Pony" is a reference to Johnny and the Moondogs, one of the earliest names the band used before settling on The Beatles.
20. "I'm So Tired"
Sir Walter Raleigh, the 16th-century explorer Lennon curses out on "I'm So Tired," was responsible for introducing tobacco to England. This is his way of venting his frustrations about being addicted to smoking.
21. "Dig It"
"Dig It" originated as an improvisation that flowed out of the band performing a cover of Bob Dylan's "Like a Rolling Stone" while jamming in the studio.
22. "I've Got a Feeling"
"I've Got a Feeling" was the last song Lennon and McCartney wrote together, and their first true collaboration since composing "A Day in the Life" three years earlier. They merged two songs they had in the works, McCartney's "I've Got a Feeling" and Lennon's "Everybody Had a Hard Year," when they realized the songs had identical tempos. Lennon also wrote the riff at the start of the finished song.
23. "Hey Jude"
Paul McCartney asked the 36 musicians brought in to perform George Martin's orchestral score on "Hey Jude" to record another track with them all singing and clapping along with the "Na-na-na-na, hey Jude" coda, but one of them reportedly refused and walked out, saying, "I'm not going to clap my hands and sing Paul McCartney's bloody song!"
24. "The End"
Ringo had to be pushed hard to record his drum solo in "The End," as he absolutely hated drum solos. Paul McCartney said in an interview in 1988 that when Ringo joined the band, "We asked him, 'And what do you think of drum solos?' and he replied, 'I hate them.' We shouted, 'Great! We love you!'"
Most of this was sourced from All the Songs: The Story Behind Every Beatles Release by Phillipe Margotin and Jean-Michel Guesdon. It is an extremely thorough book.