The zheng is an ancient Chinese string instrument that closely resembles the zither: it consists of a flat rectangular wooden sound box over which 13 to 25 strings are stretched, supported by moveable bridges. The bridges separate the strings into two sections: those on the right are to be plucked and strummed, and those to the left are pressed to produce vibrato and other special effects. Historical sources place the zheng as far back as two thousand years, and at some point it was used by court orchestras. But for the last thousand years or so, it’s been best-known as an emblem of cultural refinement–a necessary companion for the scholar-bureaucrat. At this free lecture-demonstration, the performer will be Evanston resident Wei-Tsu Fan, who began studying the zheng as a teenager in his native Taipei. The program of rearranged folk tunes and recent compositions, designed to display the instrument’s versatility and wide appeal, includes pieces for festive occasions, poetry recitations, and philosophical contemplation. Monday, 12:15 PM, auditorium, Harold Washington Library Center, 400 S. State; 747-4850.