Leonard Bernstein’s first national television appearance, on the program “Omnibus,” saw him emerge as America’s foremost bridger of the gap between high art and popular culture. But strangely, the “Omnibus” shows aired only once, and the tapes have never been released to the public. “The reason is the entire “Omnibus” series, which ran almost continuously from 1952 to 1961, is stored on kinescopes in Wesleyan University’s cinema archives and is the victim of a legal stalemate between Wesleyan and the families of Bernstein and “Omnibus” creator Robert Saudek.”