"You Don't Wanna Hear That For Another Half Hour, Do Ya?"

During the two note bass piano from Ray, during the quieter parts of "When the Music's Over", as the tension builds with the audience waiting for "We want the world...." finally Jim says "You Don't Wanna Hear That For Another Half Hour, Do Ya?" which was I was thinking at the time, and thought it was hilarious as he gets metaphysical and not taking the song TOO seriously, at least for a second, and then screams his guts out.

Does anyone know what show it is? I might have heard it more than once.