The biggest (but not only) caveat about this recording of I Vespri siciliani is the sound quality. Other versions of the performance have been released at least half a dozen times, which is a testament to its vocal quality over its sound. This version is less noisy than some, but it's distractingly boomy. It's a dinky-sounding recording; everyone -- the soloists, the chorus, the orchestra -- seems reduced, diminished, sometimes remote. The quality of the first act is the worst, and things do improve somewhat, but the beginning is marred by innumerable squawks, buzzes, fluctuations in volume, and bleed-through. By the second act, those issues seem mostly to have been resolved and return only sporadically; what remains is a mediocre, distant sound with considerable tape hiss, which is usually at least listenable without causing flinching.
Erich Kleiber leads the chorus and orchestra of Maggio Musicale Fiorentino in a vigorous reading of the score, but he makes some substantial cuts. The overall performance is not entirely consistent. The ensemble, especially at the beginning, is especially ragged. If the chorus and orchestra are not stellar, the soloists are exceptional and account for the perseverance of this performance, in spite of the recording's other deficits.
Callas gives a lustrous performance, absolutely secure, radiantly lyrical, and deeply expressive. The quirks that tended to mar her sound later in her career aren't evident; her performance alone makes it well worth plowing through the execrable sound. She is surrounded by a distinguished cast whose performances provide a fitting context for her star turn.
Boris Christoff's Procida is complex, dark, and furiously forceful. Giorgio Kokolios Bardi is little known, but he is an Arrigo with real presence, and his singing is lyrical and heroic.
Enzo Mascherini brings warmth and dramatic energy to the troubled Monforte. The ensembles that bring the four together at the end of the fourth and fifth acts, while sonically unbalanced, are vocally and dramatically thrilling. The extraordinary singing will motivate fans of larger-than-life, old-fashioned operatic performances to persevere through the poor sound of the recording.