Not jealous - I was there.Led Zep at the Mecca Sunderland
Mecca on Friday nights, Rink (Top Rank) on Saturdays and Mecca on Sundays.
Seen quite a few at both at that time including; Ten Years After, Ginger Baker's Airforce, Free (at both including Free Live recording), Family, Quintessence, Jethro Tull more than once (one might have been at the Bay and another at the Empire).
Lindisfarne(before they were famous) at the Mecca one Sunday night - hell on because we had to pay 10p to get in and Sunday nights were usually free.
John Martyn loads of times here there and everywhere
I could go on.
Bob Dylan and Van Morrison in the jealous category - I had tickets but was working away and had to give them away