In olden days (!), Gounod's opera Faust was performed in its entirety.  That makes for a very long evening.  Having recently caught a Met broadcast on Sirius radio from 1972 with Domingo, Zylis-Gara and Tozzi (as a marvelous Mephistopheles!), I can attest that it took forever, however gorgeous the performance was!  The scene that is normally dropped for both time and dramatic reasons is the Walpurgis Night Scene.  Let's take a listen to some of the music from that scene.