Ernest- I'm from Friedberg, about 30 km north of Frankfurt a.M.
We have a pub called Trompetchen; every second friday of the month there is a jazz session. The pub is in a small cellar, amplification would deafen the audience.
The Friedberg Society for German-Irish Understanding has sometimes folkies playing Irish music (solo to trio ore more). They had to leave their home and are meeting now in a pub called Galerie until they find a new club home.