Verdi's Requiem was inspired by the deaths of two of Italy's beacons of culture and identity: Rossini and Manzoni. The seed of the work--the concluding "Libera Me"--was Verdi's contribution to a failed attempt at honoring Rossini with a requiem written jointly by 13 leading Italian composers. In late operas like Aida and Otello, Verdi's music seeps into the libretto's cracks, perfectly matching the shifting moods and events. Similarly, his Requiem illuminates the Latin texts with writing so highly charged that his contemporary, the conductor Hans von Bulow, famously referred to the mass as "opera in ecclesiastical robes." Verdi's range of expression--from hushed solemnity to aching tenderness to frightful fury--is breathtaking. David Zinman leads the CSO and chorus with soloists Sondra Radvanovsky (soprano), Yvonne Naef (mezzo-soprano), Giuseppe Sabbatini (tenor), and Ildar Abdrazakov (bass), all of whom have powerful operatic voices. CSO Chorus director Duain Wolfe gives a preconcert lecture at 7 PM. a 8 PM, Orchestra Hall, Symphony Center, 220 S. Michigan, 312-294-3000 or 800-223-7114, $22-$199. Also Fri 6/15 and Sat 6/16, 8 PM.