CALLAS AT JUILLIARD: THE MASTER CLASSES. By John Ardoin. 300 pp. New York: Knopf, 1987. $24.95
VERDI: A LIFE IN THE THEATER. By Charles Osborne. 360 pp. New York, Alfred A. Knopf, 1987. $22.95
HANDEL'S OPERAS 1704-1726. By Winton Dean and John Merrill Knapp. Hardbound, 751 pp. Oxford: Clarendon Press, 1987