OPERA

Opera Turnarounds: Soprano Karen Beardsley will sing Marzelline in the Music Center Opera production of “Fidelio,” which opens the season with a five-performance run Sept. 4. She replaces Elise Ross, who decided that the part--new to her--was too high for her voice, according to a company spokesman. Beardsley made her debut with Music Center Opera in June, singing the role of Max in “Where the Wild Things Are.” In other changes to the announced season, David Pountney will make his local debut directing “Elektra,” which opens Feb. 23. Additionally, George de la Pena and Heather Toma have been cast as the lead dancers in Mark Morris’ ballet segment of “Nixon in China,” opening Sept. 11.