Also scheduled to appear are Natalie Dessay, Mirella Freni, Karita Mattila, Ruth Ann Swenson, Stephanie Blythe, Olga Borodina, Susan Graham, Denyce Graves, Waltraud Meier, Dolora Zajick, Juan Diego Fl‹rez, Marcello Giordani, Ben Heppner, Salvatore Licitra, Ram‹n Vargas, Dwayne Croft, Thomas Hampson, Dmitri Hvorostovsky, Ildar Abdrazakov, James Morris, Ren_ Pape, and Samuel Ramey.

With music director James Levine sidelined by an injured shoulder, the concert will be conducted by principal guest conductor Valery Gergiev, Marco Armiliato, James Conlon, and Patrick Summers.

The event will begin at 5:30 p.m. It will be broadcast over the Met's international radio network starting at 8 p.m., and will be taped for telecast on PBS on June 1 at 9 p.m. (check local listings). Rudolph Giuliani, the former mayor of New York City and an opera lover, will host the television broadcast.

Volpe, the Met's 16th general manager, has served in the post since 1990; only Rudolf Bing and Giulio Gatti-Casazza have had longer tenures. He is also the first person to rise to the top job from within the organization, having served as apprentice carpenter, master carpenter, technical director, and assistant manager for operations over a 42-year career.

Peter Gelb, most recently the president of Sony Classical, will replace him on August 1.