"(Last Night) I Didn't Get to Sleep at All" is a song written by Tony Macaulay and performed by The 5th Dimension with instrumental backing from L.A. session musicians from the Wrecking Crew. The song reached #2 on the adult contemporary chart, #8 on the Billboard chart, and #28 on the R&B chart in 1972. The song appeared on the band's album Individually and Collectively. It became a platinum record.

The track was produced by Bones Howe and arranged by Bill Holman.

Tony Macaulay began work on the song while in Tokyo for the World Popular Song Festival of 1972: he met fellow-attendees the Carpenters and was inspired to write a song emulating their hit "We've Only Just Begun" (Macaulay - "I liked the feel of that, the shuffle feel of it"). Macaulay recalls that due to changing time zones "I was awake all night and sleeping all day [in Tokyo]. So I just got up in the night and I wrote it": although he was having sleepless nights it was not the song's lyric but its melody that Macaulay wrote in Tokyo, the lyrics being completed after his return to London "(quote) in a taxi stuck in a traffic jam in London, in about an hour going from one side of London to another". Macaulay sent a demo of the song to the Carpenters "(quote) They said they loved it and they'd do it. [Later] I got a phone call about 2 o'clock in the morning that woke me up (they hadn't figured out the time change between here and America). They said 'Oh, we can't record it because it mentions sleeping pills and they are drugs and we don't mention drugs.' So I got up in the middle of the night and rewrote the last verse without the sleeping pills." However Macaulay was not happy to change the lyric and Bones Howe contacted him the next week Macaulay pitched "(Last Night)..." for the 5th Dimension who recorded it with the sleeping pill reference intact.

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