Wasn't the only source for that though was it? We also had older kids at school, our own/mates older older siblings, youth clubs, other midweek soul clubs and then at the allnighter, Dave Evison's spot and a smattering of oldies played as part of other DJ's sets. You could also lean a hell of a lot in the back bar too.
After a dabble I got bored with M's after a month or two and this coincided with getting my head around what made the main room unique in atmosphere and opportunity to hear exciting new sounds. I could hear Trampoline, Time is Tight and countless Bob Brady records at home. M's also recycled tunes that had previously been big in the main hall which seemed really pointless to me. Meanwhile I'd be dancing to stuff that I didn't know almost every week as jocks introduced their new stuff so frequently.