Everyone says Pink floyd, but you gotta go deeper and more obscure for the best with those guys:
Echoes from the album Meddle.. 28 minutes long, 90% of it fantastic.
If you like that, go for Live from Pompeii
...
Here is the studio cut with some shitty dolphin footage
Pt1 :
https://youtube.com/watch?v=FwHseV3wRQQ
Pt2 :
https://youtube.com/watch?v=UumWLKO5oeg
not the whole thing....
...
Here is the combination of those 2: echoes performed live at pompeii:
1:
https://youtube.com/watch?v=Hurn3-Y2b1g
2:
https://youtube.com/watch?v=6y1bT...eature=related
3:
https://youtube.com/watch?v=HqmJK...eature=related
4:
https://youtube.com/watch?v=rLjXg...eature=related