He is, in short, a musical square. But Kastle is a gifted composer of song cycles and choral works, and a man with ideas about opera. This week Composer Kastle and his ideas re ceived a nationwide airing: in a two-hour telecast the NBC-TV Opera gave Deseret, the first work to be given its premiere on the show since Stanley Hollingsworth's La Grande Bretêche four years ago. Deseret derives its title from the state established by Brigham Young and...