Whilst he is known to sing at some concerts (including a rendition of "This Guy's In Love With You"), the only official release with Cooke on lead vocals is "The Monkeys Are Breaking Out of The Zoo" on the charity compilation Colours Are Brighter spearheaded by Cooke himself. He is a founding member of the band, although he did not officially join until their third album (he was prevented from doing so because his other band, Hardbody, was under contract with Sony). Cooke also plays in the ska band The Amphetameanies and appeared on the 2007 Idlewild album, Make Another World
Cooke is said to have had an influence on other Scottish based bands, including Franz Ferdinand (who incidentally were given a bass guitar by Mick, leading to the formation of the band), whose members appeared in Belle & Sebastian's enigmatic early promotional photographs. According to Belle & Sebastian's website, he has a degree in pharmacology.