[graylights]

Well plenty of books are the same. Meant to be consumed, used up and then just take space.

But a quality reference book doesn't really have an analogue in music. That book can be a key tool to someone performing their profession. This applies even in a digital medium.

[dharma1]

Music usually performs a different function to non-fiction books in terms of conveying practical information, but an analogue for a quality reference book could be an original composition recorded by a master musician/composer. That recording can be a key tool to a another musician or composer learning her trade, no?

Whether the book or recording is digital or not doesn't really matter