George Marek has had as much to do with the health of the operatic recording industry as any other living American; he is vice president and general manager of the RCA Victor Record Division, which puts him in constant touch with the leading operatic musicians of the world. His fifth book on the subject is an ""essay in affection"" in which he has attempted to reveal the basis of his belief that since opera is ""not a wholly musical experience"", its audience should accept, as readily as its musical identity, its non-musical one. He addresses himself to the unities of ten operas: The Marriage of Figaro, Don Giovanni, Fidelio, Carmen, La Traviata, Otello, Tosca, Turandot, Die Meistersinger Von Nurnberg, and Der Rosenkavalier. He lists composer, librettists, first-performance data, initial and subsequent critical reception, and cast of characters, with vocal ranges of the roles. Then he expounds upon dramatic and musical structure (though with no notated examples), literary allusions in the libretto, parallels between opera and original, and all the hundred-and-one subtle reasons why these ten have been among the most durable and best-beloved in the international repertoire. There may be a great clamor for a second volume to cover Aida, La Boheme, Rigoletto, perhaps even the Ring Cycle... but for the time being Marek has made a significant beginning.