The "Problem" With Film Musicals
Since film is a more naturalistic medium than the stage many directors of film musicals have
solved the "problem" of having people singing in otherwise non-musical situations in various
ways. Confining the musical numbers to situations in which singing is natural("Cabaret"),
presenting the musical numbers as fantasy("Chicago") etc. In "Godspell" you have the empty
city which gives the bulk of the film a fantastical quality.