Instead of feeling shame and pretending that you don't know your own pickney in public wouldn't it be easier to tell him that you don't agree with it, its anti-social behaviour an get him some headphones. If won't use the headphones then tek way the phone.The alternative is to not really do anything about his behaviour and then have him come home crying when a big person like me tells him to to turn his rubbish tinny music off on the bus.