Well it's the main issue. The idea of an abstract answer to the theme was fun but the result can be unclear at first.
And the other point about the gameplay is linked to it. As it is, I really like the main gameplay loop, it's fun to mess with, not too hard, and is not too bad to understand. Making it different to try to fit the theme more in an other way than the initial idea doesn't felt right to me. So I choose to keep this idea of a musical link between physical objects and I'll hope for the best.
(Also if you look at the rules the interpretation of the theme is pretty free and doesn't really affect the rating or anything)