Even images, from an analysis perspective are far more than 2D. Think of the problem space: the types of lines, shading, coloration, blending of colors, overall

Even images, from an analysis perspective are far more than 2D. Think of the problem space: the types of lines, shading, coloration, blending of colors, overall structure, etc. All of this must come into play with style transfer. With music, it's much more complicated due not only to the time domain, but also to the emotional content, the interrelationships of rhythm, tempo, chordal progressions, expression, timber, transitions from the simple to the complex, the way the music is layered, and how all these things are perceived by the listener. Like human faces, music elicits an emotional response that runs deep, and whereas the emotional content of a picture is relatively static, music's emotional content is dynamic and evolving. Music has its own "uncanny valley" between the machine and the human. Think of a MIDI track that is generated by precisely laying out notes and velocities on a piano roll, vs. a track that is recorded live and captures the dynamics of the player. The difference is immediately obvious, and that with a track that is composed by a human.