In the 50s and 60s Roberta Peters reigned as the all-American belle at the Met, specializing in soubrette roles that suited her pert, pretty looks and light, charming voice. She was never a great diva. But what she lacked in natural talents she made up in the acting department. Her Ariadne (in the Richard Strauss opera) might have been short on hauteur, but the reviews praised Peters for her persuasive portrayal of the grief-stricken heroine. By the time she retired from the Met in 1985, Peters had also earned a reputation for her industry, having essayed more than 20 roles in about 300 performances. No stranger to Chicago, the 63-year-old soprano has cultivated a loyal following here over the decades. If only for old time's sake, many of her fans are likely to turn up at this gala kicking off the annual summer-long Grant Park Music Festival. Peters may no longer be supple vocally, but she can still sing with feeling. She's slated to regale the audience with a Mozart scena ("Voi avete un cor fedele"), a coloratura showcase by Bellini ("Casta diva" from Norma), arias from Verdi operas, and surefire operetta crowd pleasers by Lehar. Making his Grant Park debut is Yoel Levi, a young conductor trained in Israel who's now music director of the Atlanta Symphony. The orchestral portion of the hefty program consists of Verdi's Overture to La forza del destino, Samuel Barber's Second Essay for Orchestra, and Stravinsky's ground-breaking The Rite of Spring. Friday, 8 PM, Petrillo Music Shell, Grant Park, Columbus and Jackson; 819-0614 or 800-343-3332.