I Do (The Castells song)

"I Do"
Single by the Castells
B-side"Teardrops"
ReleasedMarch 9, 1964 (1964-03-09)
RecordedNovember 1963 (1963-11)–January 1964 (1964-01)
Studio (Hollywood)
Length1:47
LabelWarner Bros.
SongwritersBrian Wilson, Roger Christian
ProducerBrian Wilson
The Castells singles chronology
"Some Enchanted Evening"
(1963)
"I Do"
(1964)
"Could This Be Magic"
(1964)

"I Do" is a song written by Brian Wilson and Roger Christian, originally released as a single by American vocal group the Castells on March 9, 1964. The recording was also produced and arranged by Wilson. The song's lyrics illustrate a young man getting ready for marriage. Its melody was derived from "County Fair", a song Wilson had earlier written for the Beach Boys.

According to Keith Mansfield, "the song didn't do much for the Castells, but it was a memorable experience [for Chuck Girard]". Musicologist Philip Lambert noted: "The 'I Do' intro is directly inspired by the instrumental accumulation in 'Be My Baby' and in the earlier [Phil] Spector production of the Crystals' 'Oh Yeah Maybe Baby' (1961), which have similar rhythms and instrumental combinations."