Armenian soprano Hasmik Papian, possibly the most talked-about Norma in the world today, will sing the role for the first time at the Metropolitan Opera next season. She replaces Maria Guleghina for the first four performances of the Bellini opera's fall 2007 run at the house.

Norma, considered one of the most difficult roles in the entire soprano repertoire, has become central to Papian's career: she has sung it at companies from the Vienna State Opera and Netherlands Opera to the Washington National Opera and the companies of Detroit, Denver, Baltimore, Warsaw, Turin, Marseilles and Montreal (among others). Just last month she did a run in Montpellier, replacing an indisposed colleague on short notice.

This 2006 comment from The Denver Post's Kyle MacMillan is typical of the critical reception Papian's Norma receives: "Most important, she adroitly handles the role's nonstop vocal demands — the two-octave leaps, devilishly intricate ornamentations and fast-shifting dynamics — with near-perfect articulation and stunning phrasing, every note in place." And Philip Kennicott wrote in The Washington Post in 2003: "Her singing is gorgeous. The coloratura display was accurate and on pitch, and well woven into the larger, lyrical fabric of the role." It's no wonder that Peter Gelb's Met has brought her in for the part as soon as it could.

Guleghina, in her turn, is taking over from Andrea Gruber the role of Lady Macbeth in the Met's autumn performances (October 22, 26 and 31 and November 3) of Verdi's Macbeth; that run ends just nine days before Norma opens. But Guleghina will sing Norma, also for her first time at the Met, for the remaining four performances through December 7.

The production the two are sharing is a revival of John Copley's staging, with bel canto specialist Maurizio Benini conducting. Mezzo Dolora Zajick sings Adalgisa, with tenor Franco Farina as Pollione and basses Vitalij Kowaljow and Hao Jiang Tian sharing the role of Oroveso.

To make way for her Lady Macbeth, which she will be singing for the first time at the Met, Guleghina is giving up another big Verdi role this fall: Aida. Filling in for her on September 29 and October 4 and 16 will be Angela M. Brown, whose first performance of the role at the Met (her house debut, in 2004) made page A1 of The New York Times. Brown will sing Aida as previously scheduled on November 2, 5, and 8, but she is turning over her October 20 matinee to Micaela Carosi, who is already scheduled for October 24 and 27.

The Met is presenting Macbeth in three installments next season: fall, winter and spring. Gruber remains scheduled for the spring run (May 9, 13 and 17), but has withdrawn from the January performances (5, 9, 12 and 15). Her replacement is yet to be named.

Those ladies are not the only sopranos whose Met schedules for next season have changed.

Maija Kovalevska, who sang Euridice in Mark Morris's new production of Gluck's Orfeo ed Euridice this past May, sings her first Met Micaлlas in Bizet's Carmen on February 4, 8, 13 and 16. She replaces Krassimira Stoyanova, who will still sing the role as previously scheduled on February 19, 23 and 27 and March 1.

And Ekaterina Siurina will take over from Isabel Bayrakdarian the role of Susanna in Mozart's Le nozze di Figaro for the November and December performances (Nov. 10, 14, 17, 21, 24 and 28 and Dec 1); Bayrakdarian remains scheduled for the October performances (2, 6, 10, 13 and 18.)

If you need the proverbial score card to keep track of all this, visit www.metopera.org.

By Matthew Westphal