There's a lot of material in the play about Cassie, but here are some main points:
Cassie is returning to the line. While she is a strong woman, she is at the borderline, and has had to face a lot of disappointments and swallow a lot of pride to come to an audition for general chorus.
Whereas Paul has a huge monologue in words, Cassie expresses herself through her dance. It's very important through movement and lighting that she communicate, fear, love, rejection, desire, passion, and perserverance through her dance. A tough job!
Cassie was in part based on Donna McKechnie, and also others, including LeLand Palmer (Primarily Zach and Cassie's failed affair).
Cassie wears red as a way to stand out to her former lover, Zach. Also, in the Opening, she does not sing, underlining her difference from the other auditioners. This should be choreographed by the director pointedly.
Hers is the only discordant introduction in the "Names" section. It gives the audience foreshadowing that her story will be completed later. Her full name is Cassie Ferguson, and I believe I read she is supposedly from Minnesota.
She is also 32, which makes her tie with Greg, Connie as oldest. This is useful when Sheila is talking about how old she feels when she's 30.
As an experienced gypsy and semi-star, many of the other auditioners either know her (and vice versa) or she is recognized by them. For example, she is supposed to be old pals with
Sheila (which is part of the reason she stands next to her), and she'd probably know Greg, Connie, Mike, Al, Judy, Bobby, and Diana well, as well as others periphially.
Her lines in the montage show she does have a lot in common with the other auditioners, as far as adolesence is concerned.
She also has no lines in the "Alternatives" scene; she's already gone to "what if she can't dance any more" and come back with her solution: start again.
The second Cassie/Zach scene is as much about Zach as it is about Cassie. This gives the audience a chance to know Zach. Further characterization is explored in the Paul accident scene when we see how well she holds together when Zach starts to lose it
Originally in the show, Cassie was not going to make the final cut. The actress Marsha Mason (The Goodbye Girl) campaigned to have Cassie make it so that "Someone could always go home again."
Another interesting story is that in an early version of the play, Cassie came in with a "star" entrance, late, in a lam`e jumpsuit and asking for change for a taxi. This made her totally unsympathetic, so that's why she has had to face her own failure before she came to the audition. (Ironically, this opening was somewhat recreated in the movie)
Finally, Cassie is somewhat shy and definately a tender hearted person. The character of Maggie is also based on Donna McKechnie and was later separated. While this cannot be used in an obvious connection between the two characters, you can get a sense of a
different part of Cassie by looking at Maggie.
