The Lyric Opera of Chicago doesn’t have to give anything away: its productions perenially sell out, even at ticket prices that range up to $145. But fortunately the organization also remembers the populism of 19th-century opera, and for two years running it’s presented a free concert in Grant Park at the end of summer. The impressive roster of singers for Saturday’s extravaganza is drawn largely from the first two productions of the Lyric’s upcoming season, Verdi’s Otello and Kurt Weill’s Street Scene. The two leads from Otello–tenor Ben Heppner (Otello) and soprano Renee Fleming (Desdemona)–will be singing, separately, in selections from Rusalka, Der Rosenkavalier, and Andrea Chenier; also performing are baritone Lucio Gallo (Iago), tenor Jonas Kaufmann (Cassio), and soprano Kallen Esperian (who’ll take over for Fleming late in the run). From Street Scene the program features soprano Catherine Malfitano (Anna Maurrant), tenor Gregory Turay (Sam Kaplan), and baritone Timothy Nolen (Harry Easter); though Malfitano has been getting a lot of media attention for her versatility and compelling acting, the relatively unsung Nolen is her equal in those departments. With his forceful, nuanced voice, he can convey a wide palette of emotions without resorting to ostentatious display. His eclectic repertoire includes Mahler songs, Wagner operas, and Sondheim musicals (he was especially notable as Sweeney Todd); a favorite of composers, he appeared in the first performances of Bolcom’s McTeague and A View From the Bridge. Here he’s slated to sing “Ein Madchen” from The Magic Flute, as well as the lines that bridge the final trio and duet in Der Rosenkavalier. Rounding out the roster of singers are soprano Stacey Tappan, a member of the Lyric’s Center for American Artists, and mezzo-soprano Susan Graham, who will play Hansel in Engelbert Humperdinck’s Hansel and Gretel this winter. The Lyric’s orchestra will be conducted by music director Andrew Davis. Saturday, September 8, 7:30 PM, Petrillo Music Shell, Grant Park, Columbus and Jackson; 312-827-5925 or 312-332-2244, ext. 5600.