So... can't deny I'm a bit of a prog-head. I do like tunes that go past the ten minute mark when they have great musicianship, a concept that is allowed space to breathe and lyrics that really get to grips with what the band are going on about. Bands like Rush, Marillion, Dream Theatre, Floyd, Zeppelin, Maiden, etc...
Not to everybody's taste, I agree. And for the record, one of my fave songs ever is The Smiths 'Please Please Please Let Me Get What I Want', just under two minutes and absolutely perfect...
But this is a thread about dem LONG songs... what's one you really like, if this is the sort of thing that floats your boat?
It's
my thread, so I'll put a ten-minute minimum on potential nominations!

I'll give you 'Gaza' by Marillion... a band best known for soft rock in the 80's but nowadays they're kinda like Peter Gabriel with a bit of Floyd and Dream Theatre thrown in, great band, and this track is 17 minutes of awesomeness.
https://www.youtube.com/watch?v=W6sioMr7j0IAnyone wanna join me in this one?
