We describe a biophysically motivated model of auditory salience and present results which show that the derived measure of salience can be used to successfully identify the position of perceptual onsets in a musical stimulus. We evaluate the method using a corpus of unaccompanied freely sung stimuli. We briefly show that perceptual onsets detected by the model are in good agreement with those identified by a combination of state-of-the-art algorithms and manual correction. We show that this continuousmeasure of salience can be used to track and predict rhythmic structure on the basis of its periodicity, thus avoiding the necessity for ad hoc decisions as to if, or when, an event has occurred.