My DD had the same insane intensity for learning very early on and reading literature books fluently by her third birthday and equally strong in math. She also went through astronomy phase. It all started with the moon. Anyway, I thought we were looking into college by 13 or earlier.

Right.

Now a rising second grader, she is so indifferent about "school work." She thinks school is a big waste for time and she just wants to learn the next big concerto or work on her own composition. We might have to move so she can attend a music pre-college.

Kids change and sometimes, dramatically so. I would focus on meeting his current needs while gathering information about available choices.