The forces of time and of craft can turn the finest of wines to cognac -- or to vinegar. And so with the human voice. When the voice is that of Luciano Pavarotti, some may miss the delicate flavor of the voice of old, but many more prefer to relish in its darkened strength and constant passion. Or so it seemed to a huge crowd that cheered the tenor through two encores last night at Constitution Hall.

In truth, Pavarotti's voice is a lyric gem whose perfect focus allows the illusion of size, an illusion which may have led him into heavier roles in recent seasons. Those roles, or perhaps just nature, have left their mark. The appoggiature sounded forced in three early arias by Bononcini, Caldara and Durante that opened the recital, and there was strain in his formerly effortless bel canto technique. If scaling the vocal heights in soft tones was often a problem, the blend of head tones and full voice proved an unhappy one -- particularly in Tosti's "Serenata" later in the evening.

Yet by the end of the "Ingemisco" from Verdi's Requiem, the voice had found its placement, and the tones were rich and gorgeous. When all is said and done, Pavarotti's voice remains one of the most ravishing sounds in nature. Last night it soared through Bizet's "Agnus Dei" and surprised all with its disembodied textures in Schubert's familiar "Ave Maria."

Into the night, his impeccable diction and impassioned conviction lent a powerful flavor to a set of 10 songs by Tosti. His support proved almost faultless here, spinning legato lines with awesome ease. He even succeeded in creating intimacy in the DAR's barn-like acoustics. At the close there was a shower of roses and violets, and at least two adult bobby-soxers rushed on stage to kiss him. He thanked the audience with Puccini's "Recondita armonia," and again with Massenet's "Pourquoi me reveiller?" where the voice boomed to operatic dimensions and stirred with raw feeling. The ovations then continued until, with his left hand clutching the inevitable white handkerchief, he blew kisses goodbye.