Every first Thursday of a month. Organised by the community for the community and with the community. With free entry. There are jamming sessions and invited guests.
Check the playlist: https://open.spotify.com/playlist/7jOe8uYZsvEq2qALm154M9?si=FFrtWt9MQ621YazYeOKIqg&nd=1
Youtube: https://www.youtube.com/TheSessionBerlin