Themes of Musicals

I am trying to find three musicals that are of similar theme from the 20th century by different artists but with some similarities.

Broadway Musical

Doses anyone have any good ideas on how the use of costumes helped generate a mood or feeling for the audience in the Broadway musical Ragtime. What mood did they create; Did they set one race apart from another? Were costumes used in any other way to help with a certain theme? Could use any fresh ideas you might have for an essay.