The most prevalent way I see drivers listening to tunes is through their stereo speakers at a reasonable level. While probably the safest and least illegal mode of tune enjoyment, the usual songs that emanate from the open windows consist of talking about confection stores or split personalities.
Every once in a while I see a middle aged woman in her Nissan Maxima, ears clogged with plastic, trying to figure out if clockwise or counterclockwise is louder. Sometimes it's a kid (I can't believe I'm old enough to call minors kids), but usually it's some Josh Groban worshiping menopausal Layne Bryant customer. Oh, and this is totally illegal in DC (unless your iPod has a hands-free accessory that allows you to control the device by voice) and VA. If you are one of these people, please take off your headphones so you can hear me swearing at you and your (presumed) music choice.
The most annoying (and dangerous to Rockist bikers) kind of listening is the kind that has nothing to do with music. It's those darned commuters that have the most ineffective but still effective form of birth control glued to their ear. Here's my one sided version of every conversation: "No Chad, I said we'd play doubles on Saturday... Of course I'll go to the tasting, it's not like I have pilates every day... " I wish they would just put down the phones and listen to some Huey Lewis and the News... or spend time with someone who's obsessed with them.
image courtesy of Bike Snob NYC