Phil joined Genesis as the drummer in 1971 at the same time as guitarist Steve Hackett, and both play on the band's third album, "Nursery Cryme". Phil even sings a song on that album, "For Absent Friends" [1]. The band records "Foxtrot" which includes the epic 23-minute long "Supper's Ready" [2] and then the album "Selling England by The Pound", which contains two of early Genesis's best songs "The Cinema Show" [3], which has an extended keyboard solo, and "Firth of Fifth" [4], which has the Hackett's most famous guitar solo. After the next album, a double concept called "The Lamb Lies down on Broadway" (consistently rated as one of the best prog rock albums) Peter Gabriel leaves and has a successful solo career. The band continues with Phil as the singer and, after Hackett leaves a few years later, they become more pop focussed, and have a load of hit singles in the 80s and 90s.
[1] https://www.youtube.com/watch?v=cHWJ-7BUCNg
[2] https://www.youtube.com/watch?v=M58wE8GTGp4
[3] https://www.youtube.com/watch?v=G501Ii0X0NE
[4] https://www.youtube.com/watch?v=SD5engyVXe0