I read a paper about this. Apparently the first “bars” were more like irregular house shows. Someone would make a batch do ale or whatever and when it was ready they’d put a sign out front of their home letting everyone know, and people would come over to the house to drink. Sometimes they paid a flat fee at the door, sometimes it was paid per drink, or some combo of the two. Food was usually included in this arrangement, and often if anyone was around who could play music they’d perform. Eventually well off enough families would build “halls” specifically for this sort of occasion and they eventually evolved into “bars”.