“Dear Rhoda” can be performed with 17 actors but can include up to 30. 

Main Roles

Piano Man (a musician who can play jazz piano as well as 1920s show tunes)
Larry and Jerry (late 20s to mid 30s)
Donna and Rhoda (late 20s to mid 30s)
Skog (late 20s to mid 30s)
Jack Jones (30s to 50s)
Bert Weber (30s to 50s)
Boxcar Bertha (30s to 50s)
Martha Biegler (late 20s to mid 30s)
Carl Sandburg (40 to 50)
Jack Jones (40-50)
Fanny Brice (late 20s to mid 30s)
Sophie Tucker (later 20s to mid 30s)
Clarence Darrow (mid 60s)

Minor Roles (some of these can be double cast)

Jean (Rhoda’s older sister)
Flappers/Dancers (4-6 women in their 20s)
Young male dancers (4-6 young men in their 20s)
John Loughlin