Two of the best concerts I ever went to in the 70s. The first concert Pert had a drum set... The second concert a couple of years later, the entire stage was a drum set with umpteen bells, whistles and gongs.
I know the acid likely helped the second time around, but this dude could really drum.
Went to concerts often in the 1970s, saw all the greats that toured through Texas including Uriah Heep which I would say was a progressive rock band, though nothing like Rush..
Tickets were cheap then too, a concert with two front bands and the headliner was less than buying a new LP and a lot of were in the $4-5 range