The only famous chaps i saw before they were famous were Jakko Jakszyk and Joe Jackson. Not even sure if their bands stayed together, so it maybe just Jakko and Joe himself that became famous.
Anyways, myself and some buddies wandered into a pub in Gosport ( i used to live in {Portsmouth ) and there was a great band on, called Arms and Legs. We didnt know they were playing at the time, just a lucky shot
And the same with Jakkos band back in the day. I was living in Oxford after Portsmouth ( and Southsea as well ) and used to go to The Corn Dolly a lot, in Oxford. There was a band playing called The 64 Spoons. Strange crew .. but entertaining