We present a method to analyze the streaming sound output of a real acoustic violin and infer the control inputs used by the musician. In particular, we extract the following parameters: which note was played, which string it was played on, whether the instrument was bowed or plucked and the location of the bowing or plucking point from a discrete set. The approach we use, pattern classification of the short-time Fourier transform (STFT) frames of the sound signal, is general enough to enable application to almost any musical instrument.