Music Recommendation and Discovery : The Long Tail Long Fail and Long Play in the Digital Music Space With so much more music available these days traditional ways of finding music have diminished. Today radio shows are often programmed by large corporations that create playlists drawn from a limited pool of tracks. Similarly record stores have been replaced by big box retailers that have ever shrinking music departments. Instead of relying on DJs record store clerks or their friends for music recommendations listeners are turning to machines to guide them to new music.In this book Òscar Celma guides us through the world of automatic music recommendation. He describes how music recommenders work explores some of the limitations seen in current recommenders offers techniques for evaluating the effectiveness of music recommendations and demonstrates how to build effective recommenders by offering two real world recommender examples. He emphasizes the users perceived quality rather than the systems predictive accuracy when providing recommendations thus allowing users to discover new music by exploiting the long tail of popularity and promoting novel and relevant material ( non obvious recommendations ). In order to reach out into the long tail he needs to weave techniques from complex network analysis and music information retrieval.Aimed at final year undergraduate and graduate students working on recommender systems or music information retrieval this book presents the state of the art of all the different techniques used to recommend items focusing on the music domain as the underlying application.