The William McKinley Jazz Ensemble or Jazz Band is a group of student musicians at McKinley who often served as the backing band for Glee Club performances. The group's composition varies from episode to episode, though some members have been present since their first appearance in Pilot, the first episode of Season One.
Like Brad, the New Directions pianist, the Jazz Band members are (mostly) mute and are rarely acknowledged by the Glee characters. They were disbanded in New Directions, and their instruments were going to be sold to make money for two computer rooms where the Choir Room once was.
The Bassist is the first Jazz Band member to speak a line.
New Directions recruits several of the Jazz Band members in order to fill their 12-member requirement.
The Drummer is the second band member to have a line.
They do not speak but appear to have quite surprised reactions about Ryder being catfished.
Should we like, leave?