"Aida" could, and perhaps should, have been called "Amneris." It is the Pharaoh's daughter, Amneris, who propels the action and most develops as a character in Giuseppe Verdi's epic opera. Saturday night at the Benedum Center, the Egyptian princess got her due. With the last-minute appearance of beloved mezzo-soprano and area native Marianne Cornetti in the role, it truly was Amneris' night.

Even before the opening notes emanated from the pit orchestra of the Pittsburgh Opera's impressive production of "Aida," considerable drama had already taken place. Mezzo-soprano Stephanie Blythe was struck with congestion yesterday, prompting a mad scramble for a substitute who knew the role of Amneris well and was available. Cornetti was, so to speak. The former Pittsburgh Opera Center, Duquesne University and EPCASO graduate has sung the role to acclaim at the world's top houses, but she happened to be in Amsterdam, preparing for a production of "A Masked Ball."

The Opera booked her on the last seat of a flight arriving at 3 p.m. Saturday, a scant five hours before opening curtain. She was immediately thrust into a mad rush: getting her up to speed on the production's staging, fitting her for costumes and allowing her a smidgen of rest. Cornetti then had to leave Sunday to return to Netherlands Opera -- meaning she was in Pittsburgh for less than 24 hours! The offstage drama was a fitting backdrop for the grand trappings of Verdi's "Egyptian" masterpiece, and Cornetti's many local admirers (she has an active fan club) were thrilled. But she, the cast and conductor Antony Walker adapted so well it would have been hard to tell there was a late substitution. Not only did Cornetti make four costume changes, she moved with assurance, never hesitating in her role.

To my ears, Cornetti's vocal prowess has grown. She surely is entering the prime of her career. Her voice has an uncanny quality to it: it is spacious, yet soft, like a billowing cloud. Even when launching into climaxes of volume and pitch (easily hitting high notes like a soprano), she maintained a suppleness to her tone.

In an opera that includes long ceremonial trumpets heralding the Egyptian victory over the Ethiopians in the famous Triumphal Scene (this one had a horse and local wrestling legend Bruno Sammartino), it was the magnificent, trumpeting voice of debuting Vladimir Kuzmenko as Radames that rang in one's ears. The Ukrainian tenor displayed ample color and sensitive phrasing, from his opening Romance, "Celeste Aida," to his final fight with Amneris.

This was a traditional production in the grand old style, not just in blocky, formidable sets but in the purposeful movements crafted by stage director Stephen Pickover. Kuzmenko, Morris Robinson (Ramfis), Liam Moran (King) and the priests and soldiers appeared static and stately, reflecting their music, while Mark S. Doss (Amonasro, the Ethiopian warrior king) and Eszter Sumegi (Aida, his daughter) moved actively. While I can't imagine a more perfect representation of the powerful and scheming Amonasro by Doss, Sumegi's Aida was so fidgety and anxious she could have been Lucia di Lammermoor. While offering a bell-like voice, she didn't present the strength of character or the allure of the Ethiopian princess.

Choreographed by Michele de la Reza and Peter Kope, the ballets focused on angularity and heaviness -- symbolizing the monolithic Egyptian structures and stratified society. The choruses -- especially the women's chorus in Act 2 -- displayed outstanding pitch and ensemble. Chorus master Mark Trawka gets the bulk of the credit there, but conductor Walker again excellently marshaled the forces on and below the stage, with musicality and with a confidence-building authority. Several splendid orchestral solos (oboe, flute, harp) set the moods well, and the cimbasso (a special trombone-like instrument) added to the texture.

Management thinks Blythe will recover for the rest of "Aida's" run -- her role debut as Amneris. But for the audience Saturday, it was a veteran of the role that guided us through the opera and sang wonderfully, even though Cornetti hardly had time to take a breath.