Donald Crockett's chamber concerto for viola, to airy thinness beat, will be presented in a version for viola and piano (Kate Vincent and Brendan White) at the William Primrose Viola Competition and concert on June 15 at 5:30 pm in Mayman Hall at the Colburn School of Music.  Other works on the program include Andrew Norman's Gran Turismo in a new version for eight violas, and music by Paul Chihara.