Adria Sternstein Foster and Susan Robinson offer a new recording of contemporary works for flute and harp. As the principal flutist and principal harpist of the Kennedy Center Opera House Orchestra, the two have been colleagues since the mid-1990s performing for the Washington National Opera as well as Kennedy Center ballet and musical theater programming. “Iridescence” is a fitting title for a collection of music full of kaleidoscopic harmonies and vivid imagery, featuring works by Gareth Farr, Vincent Persichetti, Stella Sung, Jacques Bondon, and William Alwyn.