There were a whole spate of Jazz clubs set up in similar environments (ie Pubs) in the mid to late 1940's,to enable enthusiast to meet and share live music in congenial company.
One of the earliest and most famous was at the Red Barn at Barnehurst in Kent, where George Webbs Dixielanders featuring Humphrey Lyttleton, played for some years. The Red Barn is often credited with being the home of the "Trad" jazz revival in Britain. I suspect that with the growth of interest in Folk Music in the'50s enthusiasts where looking for a similar environment to share their chosen music, and naturally gravitated to similar venues.