The avowed purpose of this concert of African-American spirituals, held at the Second Presbyterian Church in the South Loop, is to raise funds for the restoration of the church’s 14 Tiffany stained glass windows. But the presenters must also be hoping that the lineup for “Three Generations”–baritone William Warfield, bass-baritone Benjamin Matthews, and baritone Robert Sims–will become a sort of supergroup, a la the Three Tenors. The legendary Warfield, born in Arkansas in 1920, has been a professor since the mid-70s, first at the University of Illinois and then at Northwestern, and his stage career began in the 40s. Though he’s toured with musicals, sung in operas, and performed with symphonies, he’s probably still best known as the stevedore Joe in the 1951 movie version of Show Boat, singing “Ol’ Man River.” He’s been typecast, to be sure–as Joe, as Porgy (including a stint opposite his wife at the time, Leontyne Price, who was playing Bess)–but he also participated in a postwar movement, alongside Price and Marian Anderson, that made headway toward the desegregation of vocal music; in 1983 he won a spoken-word Grammy for a performance of Copland’s A Lincoln Portrait. Warfield’s voice doesn’t have the heft, power, or suppleness it did in the 60s, but it’s still clear and robust–and he’s all but certain to bring down the house if he sings “Ol’ Man River” one more time. Representing the boomers here is bass-baritone Benjamin Matthews, who cofounded New York’s Opera Ebony in 1974 and is now in his 50s. He too has played Porgy, but he’s also landed major roles that once would’ve been closed to an African-American, like Mephistopheles in Gounod’s Faust. Though his brawny voice has passed its prime for opera, he’s developing a reputation as an interpreter of spirituals and Creole songs. The youngest of the trio is Robert Sims, a teacher at Northern Illinois University whose ardent and agile baritone can soar with ecstasy or plunge into sorrow. The program includes a few of his art-song-like arrangements, as well as selections by Jackie Hairston, Margaret Bonds, and Chicagoan Lena McLin. Sunday, 3 PM, Second Presbyterian Church, 1936 S. Michigan; 773-307-8299. TED SHEN