Forgotten heavy bands from late 60's to early 70's

King Crimson. Try Red or USA

Budgie have already been mentioned who were an inspiration for Metallica and who covered two Budgie tracks. They just chose a crap name.

Man another band from Wales the same as Budgie, created many great albums but the best was Maximum Darkness a live album starring John Cipollina from Quicksilver Messenger Service and secondly Live at the Padget Rooms Penarth.

Both albums are total rock icons.

@lordmelton - I'm a big fan of Man and that whole Welsh music scene of the 70's. I got to see them 5 or 6 times here in the San Francisco Bay Area, including that 'Live at the Keystone Berkeley' show that they released. The first time they were here was supporting Hawkwind on their '1999' tour, back in 1974.... 

@vinylvin - I don't think King Crimson are very 'forgotten'! 😄

Toad, Swiss band with members from Brainticket and lead guitarist from Hawkwind. For some real heavyosity try some Krautrock bands like Eloy, Faust, Amon Duul, Ash Ra Temple. As others have mentioned Michigan bands like MC5, Frigid Pink, Bob Seger System (2+2 total heavyosity), Stooges, SRC, Mitch Ryder and Detroit Wheels, The Underdogs, Unrelated Segments, Amboy Dukes, The Up, Sonics Rendezvous Band, Detroit (the band), I could go on and on. I got to see many of these bands around Ann Arbor when i was just a wee lad.

@larsman: You may already know, but Man's drummer Terry Williams was later in the UK super-group Rockpile, and is also heard on the late-70/80's solo albums of Rockpile members Dave Edmunds and Nick Lowe. After that he joined Dire Straits, and is now retired. A great drummer.