@Northern Voice's 30-minute clock is up and he wasn't taking this anyway.
Round 6:
Firth of Fifth -- Genesis
This was one of the major "classic rock" bands that I was surprised was still on the board, though they are not for everyone. I am going with this now because they -- and this very song -- have a chance of being sniped by Yo Mama.
Like Fleetwood Mac, Genesis is really several bands in one. They changed drastically not only from beginning to end, but with almost every album. Early Gabriel and late Gabriel bear little resemblance to each other, as do early early Collins and late early Collins and early late Collins and late late Collins (I'm gonna block out the stuff they did with that other singer.) The constant was their striving to make major musical statements. Even the poppiest Collins-fronted albums have material of stunning sweep. Gluing it all together was Tony Banks, who IMO is one of the greatest keyboardists in rock history.
Selling England by the Pound, their penultimate album with Gabriel, is the quintessential Genesis work IMO. Here, the ambition of their earliest work remains, but the production quality was significantly better and the band tried more complex arrangements and long instrumental passages than before. If someone who knew nothing about prog asked what it sounds like, as good as response as any would be to play them the best songs from this album.
To me, its greatest track, and the greatest track of their entire career, is Firth of Fifth. Banks' performance on piano and organ and Steve Hackett's on guitar are breathtaking. It's got all kinds of crazy time signatures going on, but never devolves into wankery for its own sake. This is what I turn to when I want to hear experimental music that's easy on the ears.
@Raging weasel is up.