Sort of on a Genesis kick at the moment. They started off alt or prog in the 70's, then moved toward pop and had a big hit album with Invisible Touch in 1986 which I like, too. At one time Peter Gabriel was the singer, but drummer Phil Collins took over that when Gabriel left in 1974. Guitarist Steve Hackett left in 1977 leaving the trio of Tony Banks (keyboards), Mike Rutherford (bass/guitar) and Collins (vocal and drums) whose next album was "Then There Were Three..." with the hit "Follow You, Follow Me". I stopped following them after they reformed with other people.
One of my favorites, "Firth of Fifth" from Selling England By the Pound. The version on the excellent live Seconds Out double album lacks the piano intro...which sets the mood and style. Hackett's solo in the last 1/3 is awesome.
Here's a live version of "Watcher of the Skies", which is a bit unusual with a "Morse code" beat after the mellotron intro. Gabriel's outfits, including a big fox head, got attention for the band, but the rest of the band did not care for them.
Here's how to play the mellotron part. I like watching these types of videos even though I play no instrument.
"Dance on a Volcano" from Hackett's Genesis Revisited tour of a few years ago - which I saw this past February.
Here is a 17-minute medley of the better-known instrumental parts, all played by one man. You can drag though the first minute or so if you don't want to hear WOTS again...