Misc: what gas made the hindenburg go "boom"??

Questions

Movie Musicals: "Sweet Charity" featured a young woman who nowadays, prefers past lives:?

Movie Musicals: Finish this "Oliver" song: "One boy, boy for _______!"?

Movie Musicals: George Burns, Steve Martin and others were in this musical about the Beatles:?

Movie Musicals: In "Help!", this guy becomes the target of ring snatchers:?

Movie Musicals: This 1977 movie featured the Bee Gees on its soundtrack:?