We present a system that listens to music on-line and almost instantly identifies the piece the performers are playing and the exact position in the musical score. This is achieved via a combination of a state-of-the-art audio-to-note transcription algorithm and a novel symbolic fingerprinting method. The speed and precision of the system are evaluated in systematic experiments with a large corpus of classical music recordings. The results indicate extremely fast and accurate recognition performance — a level of performance, in fact, that even human experts in classical music will find hard to match.