Between them American pianist Ursula Oppens and England’s Arditti String Quartet probably have performed more of the music of our time than anyone else. Both came up in the mid-70s and have remained steadfast champions of the new; Northwestern professor Oppens has even earned the nickname “Saint Ursula” from composers grateful for her encouragement and advice, and as a performer she’s earned their respect for the clarity and confidence with which she illuminates their scores. She and the Arditti foursome are among a handful of players to have been entrusted with premieres of works by both Elliott Carter, the most Eurocentric and establishment of the American postwar titans, and Conlon Nancarrow, the most radical and reclusive. Four of those pieces will be reprised in this inspired joint recital. Carter, who turns 90 on Friday, has experienced a remarkable creative surge in his autumnal years. Three years ago he wrote his String Quartet no. 5–a coda to the most impressive four quartets ever written by an American, the second and third of which won Pulitzers in 1960 and 1973–for the Arditti, and last summer he crafted his Quintet for Piano and String Quartet for the Arditti and Oppens; both pieces find his mastery of complex (if emotionally empty) schemes undiminished. Nancarrow–most of whose music is so temporally complex because it was originally composed for player piano, and who once commented that as long as he’d been writing music he’d been dreaming of eliminating performers–wrote his String Quartet no. 3 for the Arditti in 1987 and followed it with Two Canons for Ursula in ’88. (He died of heart failure in his adopted hometown, Mexico City, last year.) Each piece is mesmerizing in its intended hands, an ethereal soundscape that hints at but never underscores an underlying order. Also on the program are a couple characteristic but minor marvels of deconstructionism by Ives, who was a friend to the young Carter and a strong influence on the young Nancarrow. Wednesday, 7:30 PM (with a preconcert talk at 6:30), Buntrock Hall, Symphony Center, 220 S. Michigan; 312-294-3000 or 800-223-7114. TED SHEN

Art accompanying story in printed newspaper (not available in this archive): Ursula Oppens photo by Christian Steiner; The Arditti String Quartet photo uncredited.