A jam session is a relatively informal musical event, process, or activity where musicians, typically instrumentalists, play improvised solos and vamp on tunes, songs and chord progressions.

What does jamming mean in music?

To "jam" is to improvise music without extensive preparation or predefined arrangements, except for when the group is playing well-known jazz standards or covers of existing popular songs.

What does jamming mean in slang?

slang Awesome; really exciting. Man, that was an absolutely jamming party!