They clapped before Rolando Villazon sang a single note. After all, it was the star tenor's first performance since he suddenly canceled all engagements more than three months ago, for what his manager said were health reasons. So for the audience cramming the Vienna State Opera on Saturday, it didn't matter what Villazon sang - or even whether he sang. The first sighting of the slightly built Mexican tenor in the opening minutes of Massenet's Werther set off a ripple that within moments grew to waves of thunderous applause interspersed with shouts of "bravo." It was an almost unnerving outburst of warmth from what is known as one of the world's more reserved audiences. But then, Villazon isn't just any tenor. Many critics consider him as the heir in waiting to the likes of Placido Domingo and Jose Carreras. His performances with Russian diva Anna Netrebko sizzle, and the pair has been hyped up as opera's new "love couple." At its best, his voice is a mixture of silver and honey. And even if it isn't, his masterful theatrics are worth the price of even a better seat in any opera house. So news in September that he was canceling his performances until at least early this year after a series of missed performances sent out shock waves beyond the reaches of the opera world. His return Saturday set the stage for huge expectations that were mostly - but not completely - met. WHILE WONDERFULLY supple - and surprisingly strong at times - Villazon's voice was occasionally lost in the more powerful orchestral passages - and it wasn't the fault of conductor Marco Armiliato. Although he appeared to be hitting his high B's, it wasn't always apparent - because when trying too hard to be heard, Villazon's lyric tenor just seemed to top out among all those potent brass passages of the second and third acts. Villazon himself appeared to be less than completely satisfied. Miguel Perez, who described himself as a friend of Villazon from Barcelona, said the tenor told him between breaks that he was "very happy" with the first act but "not very happy with the second." "It's a very emotional evening for him," Perez told the AP. If so, Villazon put those emotions to wonderful use. On Saturday, his theatrics made him the quintessential Werther, the emotionally vulnerable, brooding young man who obsesses over a woman he cannot have, shoots himself - and dies happily in her arms after she confesses her love for him. His face and body tortured, Villazon made believers even of those who normally have trouble sitting through the opera's final 20-minute death scene. And he received a post-performance standing ovation from an audience that normally stays glued to its seats. But - dare one say it? Villazon was outperformed Saturday. AS CHARLOTTE, the woman Werther loves, Sophie Koch was flawless, her voice powerful and pliant, her physical presence commanding and her dramatics gripping. The late great Wagnerian soprano Lilli Lehmann once said a mezzo-soprano is "a soprano without the high notes." She might have had to rethink that had she heard Koch in the upper registers Saturday. If Villazon's voice was silver, hers was an alloy of precious and rugged metals forged for strength, endurance and beauty. Her Act III aria, "Va, laisse couler mes larmes" (Please let my tears flow), had stern-faced men sitting in the pricey seats reaching for the tissues. And where Villazon's French pronunciation was occasionally fuzzy, her diction was clear and precise. More fine musical work came from the pit, with Armiliato easily alternating string-quartet-like sounds from the Vienna State Opera Orchestra, with poignant woodwind and powerful brass passages as suitable underpinnings to the action on stage. Heavy and light, serious and incidental, Massenet's music was in good hands Saturday. Director Andrei Serban's staging of Saturday's version that premiered two years ago put Werther not in Massenet's 19th century but the 1950s - a time of sexual and emotional suppression that is very fitting for this opera.