That sounds like Ernie the singing bus conductor Howard. I remember him a few years earlier at Brentwood before he retired. He would sing Hev You Gotta Loit Boy or the theme song from the Beverley Hillbillies. I think he had a third song but I can't remember what it was.

The decline of that club was down to the pub going downhill after the druggies were thrown out of the High Street pubs and moved there rather than with his floor spots.

My experience is that the use of contemporary popular music in clubs followed on from the general decline in the 70s rather than being a cause of it.