FSU College of Music
http://music.fsu.edu/pr/performance-dates.htm
Music students perform at recitals. Recitals are free. They may be students and prone to mistakes, but it's still free classical music.
The FSU College of Music calendar lists all recitals as well as full performances of the University Symphony Orchestra and other ensembles, such as jazz and winds – most (if not all) of which are free for FSU students and cheap for the general public.