The music critic and author of Callas (1974) has studied ""every scrap of recorded sound by Callas that I have been able to unearth"" and offers an annotated discography that focuses on the growth of the diva's interpretive powers as well as the precarious state of the voice from year to year and the technical qualities of the discs themselves. From early 78s to the great full-length operas of the Fifties and Sixties to the most recent, painfully deteriorated performances, Ardoin listens to the voice that was ""incapable of being inexpressive,"" noting an added trill or extended phrase here, an emphasized word there, the daring choices, the breathtaking coups de thÃ‰Ã¢tre. Though an obvious and informed worshipper, he does not gush or dither, saving his infectious enthusiasm for truly incomparable sequences. So his judgments inspire trust. But, since many of the recordings under inspection are no longer--or never were--generally available, this is not primarily a buyer's guide. It is rather a cumulatively effective portrait in described sound that recognizes the limitations of its approach. Curiously successful--but only for devoted opera buffs or Callas fans who are willing to close their eyes and forget everything but la voce.