[Bill] Condon was hyper-conscious that, to fashion a musical for film, "you have to take into account the fact that there are people unaware of these musical-comedy conventions or really actively resisting them."Why would people go to see a musical if they resist its conventions? And is there any other genre in which filmmakers are so conscious of trying to please viewers who are predisposed against them?
He dreads audiences thinking, "The people onscreen are singing again, now I'm going to have to wait two minutes for the story to pick up." So Condon tries "to weave story through a song. The basic rule becomes the characters should wind up at a different place from where they began."
Michael Sragow in the Baltimore Sun on Dreamgirls: