Henry Pleasants' book like Harold Schonberg's Great Pianist, is a counter- action to ""the curious phenomenon of contemporary music appreciation that the study of history is concentrated upon composers to the virtual exclusion of performers."" Here he introduces the great singers from the castrati to Flagstad, with their voices commented upon by critics, their personal lives assessed by the author. The qualities of the instrument, intelligence, sensibility, character, are all in evidence, as are their careers on and off stage. The legendary Jenny Lind might have been her own masterpiece, but Enrico Caruso marvelously united a beautiful voice and a beautiful nature. There are singers who sang for kings--Farinelli assuaged the melancholy of Philip V of Spain for ten years by singing him the same four songs each night--singers who were the raison d'etre for great operas--Norma was created for Grisi. The life of opera has been inextricably wedded to its performers and there are a plcthora of examples here. In his cadenza, Mr. Pleasants remarks on the stagnation of singing, looks back to the eighteenth century for future excitements. His book, orthodox in conception and execution, is at once informative and heightens a desire for even more expanded reference. It should become a standard in the repertoire.