Who is Salvatore 'Sally' Sweet from Four to Score and what is their importance?

Sally Sweet is a cross dresser who Stephanie befriends when she needs someone to decode Maxine's messages for Kuntz. Sally is a very tall man who likes to dress like a woman as a gimmick for his work in a rock band. Sally discovers he likes the excitement of Stephanie's job and joins her on several outings to search for Maxine. Sally's interest in Stephanie causes his roommate, Sugar, to become jealous. Sugar is also a cross dresser. Sugar has a crush on Sally and hoped at one point that if he cares enough for Sally, he would eventually fall in love with Sugar. However, Sally is not gay and does not have any romantic feelings for Sugar. Sally's lack of feelings have no affect on Sugar, who is determined to take what he sees as obstacles out of his way. In the meantime, Sally is a big help to Stephanie in the case, decoding all the messages and providing backup on many of Stephanie's investigative trips.