A session is several players performing together over a shared song or chord progression. It can also refer to a playing situation that includes improvisation.
How to use it
Sharing the key, the tempo, the form of the song, and the ending in advance makes it much easier to play with people for the first time.
How it differs from related terms
A session is the act and the setting of playing, while a rehearsal is practice to check the songs ahead of a performance.
Listening to what the others play and leaving space where you do not play makes for a better performance.
