Boris Kroyt was the violin soloist with such conductors as Richard Strauss and Erich Kleiber. He founded the Kroyt Quartet and later was a member of the original Guarneri Quartet. Mr. Kroyt was the violist of the Budapest Quartet for 30 years starting in 1936. He joined the Marlboro Festival in 1963 becoming musically associated with Murray Perahia and Harold Wright. Mr. Kroyt played as a soloist and in chamber groups at the Frick Collection, Lincoln Center and was in residence at the Library of Congress.