I often create music while dreaming or LD'ing. Also, when dosed on psilocybin I create the most beautiful and wonderful music I have ever heard and experienced in my life...I call it the symphony of the universe.

String theory shows that humans relate and find such importance in music in their lives because every piece of matter in the universe and beyond is composed of tiny vibrating strings...it's very interesting, google it.

But I would either try new relaxation techniques, or use it to your advantage. if you can keep the music going you could use it as a connection between waking and dream life. say you're making music in your head, then you fall asleep and you're dreaming, but the music you're making is still there, you could use it as a dream sign!