The six members of Eighth Blackbird have been called athlete-poets, and their energy and precision are amazing–rhythm is to the group what wind is to a kite. One of the pleasures of a live concert is seeing how they produce the sounds that stretch the capabilities of their instruments (piano, percussion, violin/viola, cello, flute, and clarinet). Much of their repertoire was written for them, and they’re so in harmony with the music, often playing from memory, that it’s hard to imagine anyone else performing it. This program consists of six works, including two from their latest CD, Strange Imaginary Animals: Steven Mackey’s Indigenous Instruments, a collage of conversing instruments that he describes as vernacular music from a culture that doesn’t exist, and Gordon Fitzell’s Violence, an edgy exploration of what he calls “aesthetic violence.” The concert ends with Carlos Sanchez-Gutierrez’s Luciernagas (“Fireflies”), inspired by the story of reporters arriving at an El Salvadoran village where a massacre had occurred. Urgently recommended, even to those uneasy with new music. a 7:30 PM, Ganz Hall, Roosevelt University, 430 S. Michigan, room 745, 312-341-3780. F