The 19th century musicologist Eduard Hanslick pointed towards the importance of expectation in the aesthetic experience of music and some 100 years later Leonard Meyer further suggested the possibility that expectations are built upon cognitive representations of musical styles as probability systems. However, until recently, there has been surprisingly little scientific work to establish these hypotheses. In this talk, I will characterise musical expectation in information-theoretic terms and introduce a probabilistic model of auditory expectation which learns through unsupervised exposure to music. Empirical experiments have tested the efficacy of the model in accounting for the cognitive process of generating expectations during musical listening. Ongoing work will be discussed that relates the emotional experience of music to the predictions generated by the model.