As you rightly assume in 'olden times' titles were rarely used. But SING SONG would have been the most common for house gatherings and pub sing songs. In my homeland Eire house gatherings were referred to as sessions and that's still the most popular term there for pub gathrings .e open sessions0 where amateur singers and players are welcome to join in. Closed sessions - where only invited participants may join in and Tune sessions- where only instrumentals are allowed. Here in the UK pub sessions where people were encouraged to get up and sing/play were usually called Free n'easy's Then came Karaoke of course, Folk clubs Floor singing-where singers stood on the floor to do one or two songs. Later more often called Open Mic spots, Singarounds also in the Folk idiom, singers nights. And I'm sure there'll be many regional variations