The tambourine player

Billy played bass.
Roger played the drums.
John was lead guitar. And he wrote all the songs.
Mark did keyboards and vocals.
And Janet did the tambourine.
Everybody got paid equal shares.
After a while, John got pissed off at Janet because she didn’t want to sing.
“You just bang a tambourine,” he said.
Sure, she looked good on stage.
And on the posters and album covers.
But getting paid the same as the songwriter-guitarist and the keyboard-playing vocalist, they got mad and let her go.
Janet banged her tambourine solo, and made a fortune.
While her former band folded.