He and R2D2 came on and performed what we refuse to describe in any other way than this: a Death-Star-like effort to destroy music itself:
In the extended segment, the Droids team up with Luke and Leia, who, in an accidental case of foreshadowing, are played by the original brother-and-sister team with awkward sexual chemistry: Donny and Marie Osmond. The bit opens with Donny and Marie launching into a disco song about how they're in trouble. To give you an idea of how true they were to the source material, Donny starts off, "Princess Leia, our goose is cooked unless we lift off of this star!"
"Which means we don't know what a star iiiiiiis!"