http://www.yoliverpool.com/forum/attachment.php?attachmentid=23566&d=1320887314
This link is a short article in the Liverpool University student newspaper (Feb 1966) listing the groups scheduled for their charity week. The Hollies, The Fortunes, Gerry and the Pacemakers. All for a local university do at ticket prices a student could afford...:^)
The '70s weren't much different. In 1971 I saw Humble Pie and Black Sabbath open for Mountain at the Spectrum in Philly. About nine months later, Humble Pie and Alice Cooper opened for Black Sabbath at the Spectrum. Those kinds of "dance concerts" (that's what they called them at the Spectrum back then, because the tickets were for admission only - - sit or stand wherever you could) were very common, basically every week.
In 1975 ('76?) we drove from Penn State over to Bucknell to see Rush and Kiss open for Blue Oyster Cult. Believe me, the tickets for all these concerts were cheap. (By the way, that Blue Oyster Cult concert left me with a headache for three days. It was ridiculously, uncomfortably loud.)