RhythmDB is an in-memory database containing RB.RhythmDBEntry items. It runs queries represented as GPtrArray<!-- -->s containing query criteria, feeding the results into RB.RhythmDBQueryResults implementations such as RB.RhythmDBQueryModel. From there, entries are grouped by particular property values to form RB.RhythmDBPropertyModel<!-- -->s.
RB.RhythmDBEntry contains a fixed set of properties, defined by RB.RhythmDBPropType,