I think you are exactly correct. My big revelation in graduate school (music performance) was the idea that vocalizations of music "short circuit" our learning process and tend to get a performer closer to what we'd call an "expressive" or "musical" rendition. Notated music's function is simply to give a systematic way to for people to reproduce/recreate an aural experience, but it is a "lossy" format that western classical musicians have to spend years training in performance practice and interpretation to adequately recapture the expressive elements that are not easy to capture in notation but are vital for engaging performances.