Born in Quincy, Massachusetts, he began violin lessons at the age of four with Ondricek.
When he was six he appeared as a soloist with Arthur Fiedler and the Boston Pops orchestra.
At nine, he made his solo recital debuts at Jordan Hall in Boston and Town Hall in New York[1] In Aaron Richmond's Celebrity Series of 1950-51 he was co-featured with Mischa Elman, Jascha Heifetz and Isaac Stern.
[2] Professor Castleman, an avid bicycle rider, decided he had enough of the harsh Rochester, NY winters and headed to a warmer climate taking the position of Professor of Violin at the Frost School of Music at the University of Miami.
[3] In 2001 Cypres Records and the Queen Elisabeth Concours issued a retrospective CD set of the most outstanding performances in the history of the Concours; Castleman's rendition of Leon Jongen's Concerto was chosen as one of the seventeen most distinguished violin performances.