Can you think of sets of 4 songs that sound good together? Imagine you're a radio jockey and you can play whatever you want (no playlist shoved in your face by the station management).
They can be songs that seem to compliment each other musically or because of the topic. They could be songs from the same band, songs from related bands, songs from unrelated bands or whatever.
1 THEMES Anderson Bruford Wakeman Howe (from ABWH)
2 THAT'S IT FOR THE OTHER ONE Grateful Dead
(from ANTHEM OF THE SUN)
3 TIME Pink Floyd (from DARK SIDE OF THE MOON)
4 THE OCEAN IS THE ULTIMATE SOLUTION Frank Zappa
(from SLEEP DIRT)
1 BALLAD OF A THIN MAN Bob Dylan (from HIGHWAY 61 REVISIT)
2 FAT MAN Jethro Tull (from STAND UP)
3 FAT Kantner/Slick/Freiberg (from BARON VON TOLLBOOTH)
4 THE WEIGHT The Band
1 THE GREATEST DISCOVERY Elton John (from ELTON JOHN)
2 (NO MORE) THE SUBMARINER Peter Hammill (from IN CAMERA)
3 WHEN I WAS A BOY The Who (from WHO'S MISSING)
4 LATHER Jefferson Airplane (from CROWN OF CREATION)