Classical Falla, Manuel de: ''The Three-cornered Hat'' (ballet). Ritual Fire Dance. Frederica von Stade, mezzo-soprano. Pittsburgh Symphony Orchestra, Andre Previn, conductor. (Philips DIGITAL 6514 281.) - I confess a strong partiality to the Pierre Boulez recording with the New York Philharmonic, which has a grandeur and a vitality on records unique in this piece The Previn performance is very good, usually lively, occasionally a tat prosaic. The release boasts the most extraordinary sound - clean delineation from the loudest to the softest, from the most blaring trumpets and piping flutes down to the glorious rumbling of the basses. Miss von Stade is in very fine voice and sings with style and tremendous rhythmic incision. If sound is what you are looking for, search no further, for the performance is more than acceptable, without quite the magic of the more distant-sounding Boulez.