@GaryPoole
By your definition, "Monty Python And The Holy Grail" qualifies as a musical, yes? Okay, so, really only a couple of songs, but yes they advance the plot.
@GaryPoole
And "Camelot". Also, "he's going to tell" counts...sort of. That whole scene is a musical number just trying to not happen.
@ArcturusSaDiablo Absolutely. "Brave Sir Robin" is a classic movie musical song. 😜