Disclosed are various embodiments analyzing a user's interaction with his or her music library. The system generates a time series by tracking a plurality of instances of music library interaction between a user and a music library. The system also determines a distribution expressed in the time series, the distribution indicating a trend of playing a set of audio items for a particular period of time, the set of audio items being associated with a class, wherein a timestamp corresponds to an occurrence of the trend. The system associates the distribution with a triggering event and generates a recommendation according to the class in response to the triggering event.