Springer has published the second edition of Recommender Systems Handbook. It includes a chapter on music recommender systems written in collaboration between Markus Schedl and Peter Knees (Johannes Kepler University), Brian McFee (New York University), Dmitry Bogdanov (Universitat Pompeu Fabra) and Marius Kaminskas (University College Cork).

Schedl, M., Knees, P., McFee, B., Bogdanov, D., & Kaminskas, M. (2015). Music Recommender Systems. In Recommender Systems Handbook (pp. 453-492). Springer US. 

Abstract: "This chapter gives an introduction to music recommender systems research. We highlight the distinctive characteristics of music, as compared to other kinds of media. We then provide a literature survey of content-based music recommendation, contextual music recommendation, hybrid methods, and sequential music recommendation, followed by overview of evaluation strategies and commonly used data sets. We conclude by pointing to the most important challenges faced by music recommendation research."