His real name was James Mattingly II, lead vocals and rhythm guitarist. Jimmy took music and composing very seriously. He wrote The Wonders' hit song: That Thing You Do! and several ballads, which he and the group had planned to record, following their nationwide tour. Jimmy's composing talents first surfaced in high school where he wrote and performed several songs for a city-wide talent showcase in Erie, garnering him considerable acclaim and attention.

Much to the dismay of his many female admirers, Jimmy had been dating The Wonders' costume mistress, Faye, for two and a half years. After The Wonders came to an end, he continued to produce records for Play-Tone with his new band: The Heardsmen. When The Wonders were still an unknown no-name band, that was the name Jimmy wanted the band to have. Jimmy was also the main reason the band broke up. As he wanted to record his own original, ballads, Mr. White wanted them to re-record old Play-Tone songs. This is what really drove Jimmy mad, making him quit the band.