The tumultuous ‘60s zeitgeist that transformed pop music so deeply touched the classical composers of the time too (well, to some extent), inspiring concert works with overtly progressive political messages. One of the composers whose music from the period has survived the least datedly—and who in fact never treated those ideals as a passing fashion, but has continued to let them inform his work—is Frederic Rzewski. Among his stirring bleeding-heart-on-sleeve piano works, often written for his own formidable virtuoso technique, are the Four North American Ballads, grand keyboard realizations of old labor anthems, and his vast Variations on “The People United Will Never Be Defeated!”, a protest song from Salvador Allende’s short-lived Chilean presidency expanded into 36 intricately interconnected variations. He’ll play a recital of his own pieces tonight, works that reflect his interest in musical methods from minimalism to improvisation. Good Shepherd Chapel, 4649 Sunnyside Ave., gschapel.blogspot.com. $5-$15. 8 p.m. Sat., March 1. GAVIN BORCHERT

Sat., March 1, 8 p.m., 2008