I don't think I would fully agree with you on that.
My best ballet ever, giving me first place in Quadline ballet at EuroCup 1997 was:
"It's oh so quiet - Bjork"
I don't think it is very danceable (or is it)?
It is a very challenging piece to fly to with extremes changes in speed and loudness.
Sounds to me, John, that you were "dancing" with the music if you comment on the changes in speed and loudness as making it difficult. I didn't mean to imply simple to dance to - rather setting a rhythm and mood for you and the kite's movements. Experts such as yourself can certainly "dance" to a wider spectrum of music than beginners.
Myself - more stuck on very old rock and pop - my age and lesser talent showing.
If you want to dance to internal music, as btbt suggests, that is obviously fine. If you've seen videos of a courtyard full of seniors performing tai-chi in synchronization - the rhythm is there, audible or not. And if you want to completely free-style with no rhyme or rhythm - that is probably very appropriate for freestyle flying. Although music could still set a mood.
My first experience flying a dual line to music was extremely emotional for me - it was so beautiful to connect that way. But everyone is different.
Short answer - try it. If you like it, fine. If not, fine.