Like you, I often felt it would be nice for students to listen to their own
music while they work individually--afterall, I like to listen to music in
my studio. However, I found that the kids with the earphones on couldn't
hear the comments I was making to other students as I moved around the
room. The benefit of working on art in a classroom setting is that you
receive the benefit of many students' learning, hear responses and dialogue
regarding others' work. Kids with earphones cut themselves off from the
group experience and are bound to lose some things. I explained this to
the students and they seemed okay with it.
I found kids will talk more to each other about what they're doing when
music isn't too loud or distracting. I used to invite kids to bring music
they wanted to share and we'd put it on the boom box on some days (usually
at a low volume although there are times when I've been known to crank up
some rock n' roll to get the class juiced up!). There are always
complaints about the selection but everyone knows they have the same
opportunity to bring their selections in.