bonus chorus
The cousin of a vocal solo. A bonus chorus occurs during a live performance when an artist spontaneously decides to repeat the main chorus or a variation of it. They most often occur during an artist's biggest hit. It can take the form of a vocal solo, although it is not exclusively improvised.
"I had an eargasm while Judas Priest was playing "You Got Another Thing Comin'" but things got even more extreme when they threw in a bonus chorus!"