I recently went to a place called Cafe Otto in Dalston for a night of quadrophonic music by Sun Ra. It was the first time anything had been attempted in the UK with a system comprising a Techics 1210 deck, 8 Quad II mono block amps & 16 Quad ESL57 electrostatic speakers stacked around the perimeter of the audience. It was, erm, interesting.........Sun Ra is an acquired taste & although I have some of his albums the ones he recorded that were quadrophonic were pretty out there.
First record I got was Sgt. Pepper by the way, still have it & it is still immaculate, & I agree with you, the inner stamp is iconic.