Is it a typing class?

You know what, a speed-typing class is a much better example than music of a class where "traditional" accommodations would be unreasonable. However, my friend was in an analogous situation. She's hearing impaired, and simply could not be reasonably expected to pass any sort of foreign language class, so instead of asking a professor to make the "unreasonable" accommodation of waiving listening/speaking requirements, the school just waived foreign language as a required course for her. It'd be silly to prevent someone from getting a degree in math because they can't learn a new language, so waiving the requirement was reasonable. If she was trying for a degree in math and couldn't pass basic algebra without any unreasonable accommodations, then it would be a different story.

But yes, it sounds like OP's professor is being totally and completely unreasonable-- they professor probably has a very ignorant but rigid idea of what is necessary for appropriate performance in the subject area.