Professor Lenny: Essay by Joseph Horowitz
Section 1. Virgil Thomson once called Leonard Bernstein "the ideal explainer of music, both classical and modern." Bernstein explained more than that. The dozens of programs he wrote and hosted for television—including the twenty-five Young People's Concerts about to become available on video cassette—range effortlessly from Bach to jazz, rock, and Broadway. As TV time capsules, they also explore an incidental topic scarcely apparent…