Music is much more than listening to audio encoded in some unreadable binary format. It is, instead, an adventure similar to reading a book and entering its world, complete with a story, plot, sound, images, texts, and plenty of related data with, for instance, historical, scientific, literary, and musicological contents. Navigation of this world, such as that of an opera, a jazz suite and jam session, a symphony, a piece from non-Western culture, is possible thanks to the specifications of new...