I think i have this too (also play piano, have perfect pitch). I have an excellent musical memory, but i have to actually play a song / sing it out loud to hear it if that makes sense.

I do have the motion-centric imagination sense (i could "feel" what it would be like to do a layup) without physically moving.

No ability to generate audio, visuals, etc "on the inside".

Do you have an internal voice?