The nine men and women of the only independent professional choral group in Chicago sing with impeccable intonation and style. Their repertoire is an eclectic mix--ranging from the 16th century to the 21st, from classical works to African-American spirituals--and their final concert of the season, "Eighteen Lips," pulls together a typical array of pieces, all on the subject of love. They'll sing Palestrina's "Pulchra es, amica mea" ("You Are Beautiful, My Love"), an exquisite, serene work by this Renaissance master of intricate counterpoint--one of his rare nearly secular pieces, set to text from the Song of Songs. At the other end of the spectrum is a Chicago premiere, Stacy Garrop's haunting "What Lips My Lips Have Kissed," from her settings of sonnets by Edna St. Vincent Millay; it begins without words, and Garrop's subtle use of dissonance adds to the richness and complexity. The group will also perform Morten Lauridsen's lovely "Contre Qui, Rose" ("Against Whom, Rose") and "La Rose Complete" ("A Perfect Rose"), both set to poems by Rainer Maria Rilke; these songs highlight the lyrical and neoromantic aspects of Lauridsen's music, though they're not as dramatically compelling as his large-scale Lux Aeterna. Three world premieres will also be performed: "Five Bird Songs" by San Francisco composer Paul Crabtree, who tends toward humorous texts and an easy-listening style; "I Am the Rose of Sharon" by Jonathan Miller, the group's artistic director; and "Will You Be Sensible, Girl!" by local composer Paul Carey. Also on the program are Miller's "Thy Two Breasts," Ulf Langbacka's "Refrang," and arrangements of songs by Lennon and McCartney, Hoagy Carmichael, Nat King Cole, and Brian Wilson as well as the Andrews Sisters' Yiddish hit "Bei Mir Bist du Schoen." Fri 4/15, 7:30 PM, Chicago Cultural Center, 77 E. Randolph, 773-755-1628 or 1-800-746-4969, $25, $22 seniors, $15 students. See also Sunday. Free.