"T'ain't What You Do (It's the Way That You Do It)" is a song written by jazz musicians Melvin "Sy" Oliver and James "Trummy" Young. It was first recorded in 1939 by Jimmie Lunceford, Harry James, and Ella Fitzgerald, and again the same year by Nat Gonella and His Georgians. The "shim sham" is often danced to the Lunceford recording of this song.

The jazz tune was transformed into a pop song with ska elements in 1982. With the title slightly altered to "It Ain't What You Do....", it was recorded by The Fun Boy Three and Bananarama, and was included on the former's self-titled debut album, but it was not available on a Bananarama album until 1988's Greatest Hits Collection.

Terry Hall of Fun Boy Three owned a copy of Bananarama's previous single "Aie a Mwana", and after seeing an article about the trio in The Face he decided he wanted them to sing background vocals on the song, solely based on the fact that he liked their look. "It Ain't What You Do...." became a big hit in the UK, climbing to number four in the UK singles chart, and achieving a Silver certification from the British Phonographic Industry. The success of the single also prompted Bananarama to return the favour and have Fun Boy Three sing on their next single, "Really Saying Something".

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