The big news is that the masters for this set are different from the ones used to produce the earlier recordings: these infinitely clearer tapes are from the personal collection of the Earl of Harewood and were actually made for EMI producer Walter Legge. Don't get me wrong--the sound is still substandard; but every word and note can be heard. Legge wanted to hear only the singers, so the overture was not recorded. Not only can we live without it, but it allows the opera to fit on two well-packed CDs.

Callas' performance of the rebellious Austrian Duchess Elena is spectacular. Near the opera's start she must begrudgingly entertain the French with a song. Callas, using her most veiled, menacing voice, gets the double meaning from the text, dipping low into chest voice without sacrificing any stellar top notes. In her two duets with her tenor/lover Arrigo, she's magnificent as well; the second duet, in Act 4, closes with a perfect run from high C to the F-sharp octaves below. Her "Bolero" in the opera's last act is jaunty and elegant, but she interpolates a high E at the end that cracks in two before coming together again. In ensembles she's thoroughly present.

Cristoff is at his most cavernously eloquent, but the rest of the cast, in a word, stinks. Kokolios-Bardi (Arrigo) happily was almost never heard from again, and Enzo Mascherini, who could be impressive, is anything but on this recording. Kleiber's leadership is tight and tense. Yes, this is worth it--for Callas. And again, the sound is 100 percent better than on previous releases, which gets it to about a 4.

--Robert Levine, ClassicsToday.com