I don't see what's wrong with having tunes along.
You don't have to have it cranked up so you do hear a thing. Driving for one needs more concentration that riding bikes, and people normally have music in their cars.
On busy roads, I don't hear anything anyways no matter how loud the volume, so I take them off. But most of my ride is in the hills with very few cards going by, so I have my beats with me.
This is my portable unit:
http://www.ratedpc.com/review.asp?id=50
The coolest mp3 player there is. It's weighs less than 10 grams and is no bigger than a ciggarett lighter. Also, it has a cool arm band strapso it doesn't get in the way of anything.