This Friday Liebesfreud musicians Geoffrey Michaels, Philip Kates, and Charles Forbes will be playing "musical chairs" in a program of two string duos (violin and viola) and a string trio (violin, viola, and cello). Beethoven—String Trio in C minor, Op. 9 No. 3 Mozart—Duo in B flat major, K. 424 Handel-Halvorsen Passacaglia for Violin and Viola A free "Last Fridays" concert February 25 at 5:30 pm Philadelphia Art Alliance 251 South 18th Street Philadelphia, PA 19103