Ruth - is a humoristic tour-de-force for a young comedian. She should be able to play matronly but still be vibrant and full of energy. An actress who is physically different from Frederic is a great choice. For example, if your Frederic is tall and thin, consider a short and stocky Ruth. Ruth transforms from old matronly, to a knock-out beauty when she returns with the Pirate King in When Fred'ric was a little lad, so it's great to cast an actress who is versatile. Ruth has a featured solo, but doesn't have to be a polished singer. Cast a comedian who is naturally funny, and can be bigger than life. Someone who played Miss Hannigan in Annie Junior, or Mrs. Paroo in the Music Man Junior would make a great Ruth.