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


Have been a fan of hard rock/metal since high school. Always liked the heavy/physcadelic bands equally to the metal bands I grew up with Ozzy-Maiden and Scorpions ect. Recently on Youtube I discovered some heavy/physcadelic bands I was unaware of. 13th Floor Elevators-Five Day Rain-Probe Direction-The Hook and Vahalla. Are these bands albums worth persuing? Feel free to mention any other band that deserves to be heard. Look forward to your responses.
dayglow

Elf is another good band. Three very good albums. Jo Jo Gunne also. Catus was very good.

That debut by Blue Cheer was the first album I heard that had a "heavy" sound, Zeppelin's the second. The former contained the worst "music" I had yet heard at the time of its release (1968), but then in 1970 Black Sabbath's debut appeared.

Everyone considers Spinal Tap funny, right? But not Blue Cheer and Black Sabbath?!.Unintentionally, but still.....