Bottom line is that you have plenty to concentrate heavily upon during your
first hundred or two hours. I'm all for rocking-out once you get some
significant experience. But, for now, you need 110% of your brain cells
focused on the many tasks involved with flying your first long solo.

Scrap the idea of in-flight music and come back to it when you've learned
everything.


Don't think it's possible to have learned _everything_... but I would
wait on the music for a while. I remember my first solo xc; I needed
all the concentration I could get (and then some; that's why it took
me the first 40 miles to figure out why the plane kept going
off-course to the left--my left foot was resting on the rudder pedals
and slowly causing me to turn that way).

And regardless, I wouldn't go using music if I had to listen to ATC.
I guess it's only suited for cruising around VFR on a good day--or
when you're taxiing out and decide to play the first part of "Danger
Zone" grin