Songfacts®:

• "They Don't Know" was written and first recorded by the British singer Kirsty MacColl in 1979. However, a strike at her distributors prevented it from being released as a single, although it was popular on UK radio. Tracey Ullman's version, however, was a hit, and Kirsty MacColl provided backing vocals on this version: the "bay-ay-be-ee" heard just before the last verse is sung by her.
• The song has a retro feel to girl-group hits of the '50s and '60s. It's about a girl who hears from lots of people that the guy she's seeing isn't right for her. She feels that they just don't understand, as they've never heard of love.
• Kirsty MacColl wrote this song when she was just 17. She was the daughter of folk singer/songwriter Ewan MacColl, who wrote Roberta Flack's "First Time Ever I Saw Your Face." In December 2000, she tragically died after being hit by a speedboat in the Caribbean. After her death, Tracey Ullman took part in a tribute concert for her.
  
  MacColl was a highly regarded singer who got caught up in a lot of record label dysfunction. She was well known in the UK thanks to songs like "There's a Guy Works Down the Chip Shop Swears He's Elvis" and "A New England," but her only song to make much impact in America is "Walking Down Madison" from 1991. You will hear her every December singing with Shane MacGowan on "Fairytale of New York."
• Tracey Ullman is a British comedy actress who moved to the US and starred in her own TV series, The Tracey Ullman Show, one of the first shows on the Fox network and the birthplace of The Simpson, which started on the show as animated shorts. Music was secondary to Ullman - she fell into it after meeting the wife of Stiff Records boss Dave Robinson at the hairdresser.
  
  Her first single, "Breakaway," went to #4 in the UK and #70 in America. "They Don't Know" was her next single and her biggest hit, reaching #2 in the UK and #8 in America. Both songs wer on her 1983 debut album, You Broke My Heart In 17 Places. After another album in 1984 she mothballed her music career to focus on acting.
• The video features a cameo by Paul McCartney as a character named Paul. He is seen driving a car with Ullman in the passenger's seat. At the time, Tracey Ullman was filming a role in McCartney's movie Give My Regards To Broadstreet.