have domain model shaping up.
added ability to query for songs by year.
cleaned up fixtures and made factory a first class entity in domain.
added feature to find all albums for an artist.
got rid of annoying Map and pushed responsibility about knowing about Artists to Songs.
got rid of pesky second Map.
added the ability to get all artists for an album.
added some miss cases for the tests.
added ability to add audio for a song.
moved basic types to separate package.
moved interfaces to separate package.
broke up test into two features.
added feature to track the number of plays for a song.
added ability to analyze number of plays and dates for a song.
made Date implement Comparable<Date>
added ability to add tags to songs.
cleaned up names.
fixed nomenclature mismatch.
moved all query logic to anal, where it belongs.'
moved knowledge about play history into music library, so analyst can be stateless query mechanism and library can be stateful repository.