When at least semi-experienced musicians get together and pull songs out of their ass, working all together non-verbally. Almost always involves hilarious bullshit lyrics.
Good jam sesh last night man, way to pull that riff out of your ass
by bassjesus March 19, 2014
Can you define these popular missing words?
Subconsciously dancing to a song then noticing that others are doing the same, which only makes the group jam more enthusiastically.
The Black Eyed Peas can usually entise a jam sesh.
by ahhhsuraah January 19, 2011