Little Mix co-wrote this tune with former All Saints member Shaznay Lewis. The song's phone call intro and outro is a throwback to the Shaznay Lewis-penned All Saints UK #1 "Bootie Call."
The song samples De La Soul's 1991 single "Ring Ring Ring (Ha Ha Hey)", which itself borrows lyrics and melody from the Curiosity Killed the Cat tune "Name and Number."
The single version features a guest rap from Missy Elliott. Little Mix's Jesy Nelson said: "We honestly can't believe that Missy is on our song! She's been one of our biggest idols for ever - it's incredible. As soon as we thought there might be a chance she'd appear on the track we did literally everything we could to make sure it happened."
British rapper Slick Rick was originally signed up for the guest spot but pulled out just before the release of DNA.
Missy Elliott's previous collaboration with a teen-friendly female act was in 2011 when she featured on "All Night Long," a track from Demi Lovato's third album, Unbroken.
The song's beat and bassline are sampled from Fat Larry's Band 1982 single "Act Like You Know."
Pete Townshend never had a #1 UK hit with The Who or as a solo artist, but he did produce and play on a song that hit the top spot there: "Something In The Air" by Thunderclap Newman, a group he assembled.