Who is "The Spirit of Music" in the book, The Magic Strings of Frankie Presto?

The Spirit of Music is the narrator of The Magic Strings of Frankie Presto. An omniscient god-like being, The Spirit of Music knows all and relates Frankie's strange story for the benefit of the reader as if they were a casual visitor. Speaking in passionate terms and musical imagery, The Spirit of Music acts as proof that art pervades the universe and some are divinely gifted with its abilities.