While violinist Julia Fischer’s Wednesday, January 23, Princeton University Concert appearance has been cancelled because of family reasons, area audiences are fortunate that PUC coordinators have secured German virtuoso violinist Christian Tetzlaff to provide a solo program of works by Bach, Ysaye, Bartok, and Kurtag for the date. His timely Princeton performance comes right before his string quartet tour of concerts in Oslo, Cologne, London, Zurich, Freiburg, Berlin, and Paris. The 7:30 p.m. concert is set for Richardson Auditorium in Alexander Hall, Princeton University. Current ticket holders with questions should call the Concert Office for information at 609-258-2800. Tickets are $5 to $40. Call 609-258-9220 or go to princeton.edu/utickets.