[3] The song was largely written during a recording session at EMI Studios on 18 September 1968 by John Lennon and Paul McCartney.

"[4] During the session, the Beatles and the recording crew made a short trip around the corner to McCartney's house to watch the 1956 rock & roll movie The Girl Can't Help It which was being shown for the first time on British television.

"[7] "Birthday" begins with an intro drum fill, then moves directly into a blues progression in A (in the form of a guitar riff doubled by the bass) with McCartney singing at the top of his chest voice with Lennon on a lower harmony.

Coinciding with the 50th anniversary of its release, Jacob Stolworthy of The Independent listed "Birthday" at number 17 in his ranking of the White Album's 30 tracks.

He wrote of the song: "The opening to the second-half [of the album] treads familiar Beatles ground with an improvised riff that could be the record's biggest earworm.

"[8] According to the book accompanying the 2018 box set The Beatles: Super Deluxe Version, the annotation on the tape box from the session offers an alternative line-up that "explodes some myths of who played what":[9] Additional personell Paul McCartney released a live version on 8 October 1990 in the UK, with a US release albeit only as a cassette on 16 October.

[21] Even with this limited mode of distribution, the track reached number 64 on the UK Singles Chart.