If ever there was room on one's shelves for a single, comprehensive reference work for learning about the world of opera from the ground up, then this Naxos package, 'The A to Z of Opera' by Keith Anderson is one to strongly consider. Its two CDs, 1000+ pg. subject-divided book and additional online resources will take you from novice to expert appreciator of this glorious, centuries-old art form. 2015 release.