I hope this will be a satisfying answer for you, because your statements are not really making sense to me. I would not call myself artistically inclined, although I do think life would be a lot more boring without music.

If you believe that a guy reading a book is good enough for magic, why isn't reading sheet music? To me, it seems very plausible that in a world where magic sources as "waving your hands in a particular manner" or "asking your patron/god/sugar daddy very nicely" exist, magic produced by hitting the right notes is also possible.

Additionally, I would say that even in our world, music holds power (as seen by all research into its interaction with dementia, depression, concentration etc.). Speeches, war dances can envigorate people to fight battles. Also, no books without stories, no stories without storytellers (which are, coincidentally, called bards)