Deep Purple
This band had a few incarnations. The only line up for me was Ian Gillian singing and Ritchie Blackmore on guitar. Sometimes overlooked because of big names like Hendrix and Zeppelin, these guys had the ability to fill the room with sound, at a time when the 5 guys used simple instruments/amps and recording equipment.
Check out this live version of Child In Time. People talk about Plant and Daltrey's wailing voices, Gillian could throw it out there too.
If you don't want to hear the whole song go to 1:55 and listen to about 3:15 ( audience reaction is great at 2:55 .... )
They go into a fast improv section and talk about timing...check out 5:37...zombie audience still sitting there