I'm going to go out on a sort of blunt limb here. My rash, and possibly incorrect assumption is that if you're on a Blast, you don't have a mountain of miles under the saddle. That being the case, I'd recommend against the distraction of tunes while you ride. Sing to yourself, whistle, whatever, but leave the electronics at home.
Apologies in advance if this offends you, but the advice is offered in the spirit of safety.