There have been some real great hard rock bands from the 70s.
My faves would be:
The Rolling Stones
Led Zeppelin
Deep Purple
Rainbow
The Who
Free
Bad Company
Nazareth
Uriah Heep
Queen
Alice Cooper
ZZ Top
Aerosmith
Lynyrd Skynyrd
New York Dolls
Blue Oyster Cult
Journey
Boston
Heart
The Runaways
Ted Nugent
Rush
Thin Lizzy
Scorpions
AC/DC
Motorhead
Foreigner
Kansas
REO Speedwagon
Styx
Van Halen
Some great music from that era