After a year busking in Paris, where he played tenor saxophone around the streets of the Latin Quarter, Thistlethwaite moved to London in 1980.

Mike Scott heard the saxophone solo on Nikki's "Johnny Smiled Slowly" and invited Thistlethwaite to come and play with his fledgling band, The Red and The Black.

Although Thistlethwaite is mainly known as a saxophonist, he has also featured heavily on mandolin, harmonica, Hammond organ, guitar, and bass with The Waterboys and other acts.

During the 1980s and 1990s he featured as a session musician on recordings by bands such as: World Party, Fairground Attraction, Psychedelic Furs, Bob Dylan, China Crisis, Johnny Thunders, Donovan, The Vibrators, Chris De Burgh, Bruce Foxton (The Jam), and The Mission.

[4] Sharon Shannon, also a member of The Waterboys, recorded a song for her eponymous debut album called "Anto's Cajun Cousins", named after Thistlethwaite's American relatives.