Can any of you honestly say that you wouldn't want the 1812 Overture blaring out of your crotch? Or, for the less classically-inclined, La Cucaracha?(1) Actually, let's go back to the 1812 and just savor that image for a while, especially the cannon sounds. Oh yes, you'd need that subwoofer. But think of the bathroom-filling sound! And urinals, being concave, and bathrooms, typically having lots of tile and other hard surfaces, should make for great acoustics.(2)
And what else do you do in the bathroom? Generally, you're focused on one activity. Why not listen to music at the same time? Or, better yet, hook the zipper up to a radio and tune in the news when you unzip. In this modern world, it's all about multitasking. It's also handy for power outages, or other times when you need to get information but can't. Fortunately, they make flexible radio antennas these days. So even if you're lost in the middle of the woods, a quick unzipping might be enough to alert your rescuers. Or scare off bears, depending on your musical choices. The Survival Radio Zipper might just save your life!
But probably not. It's a nice feature, but the product doesn't hinge on that. I think Lictor's point about increased royalties to the people who make music will seal the deal, so to speak. And by "the people who make music", I mean the music publishers, obviously. Now that pirates are stealing all of their profits, instead of paying for the new, hip, and enormously high-quality music that the companies are churning out, they need to find a new way to make money. The musical zipper might be just the thing to save the music industry. Or else, hey, screw the music industry and just download music to your pants.
Plus, there would, as jasona pointed out, be a need for security measures to block unwanted signals. It might not stop your housemate from downloading "Jingle Cats" to your pants, but people would pay good money to avoid advertisements. Especially if you made sure that the ads were all annoying and/or embarrassing ("Say, looks like you could use a spray of Jock-U-Clean, the all-purpose jock itch medicine!").
You know, the more I think about this, the more I agree with jasona. But I'd just like to point out that the picture of the B.F. Goodrich CEO is named Burner_Dave.jpg, and I think that's just brilliant. You'd think someone named Burner Dave would be CEO of Frito-Lay or something, but I do like the idea of Burner Dave sitting around his office thinking about new aerospace products, or at least how to turn the International Space Station into a giant bong.
2)
Perversely, I expect that the most popular song module, at least for bathroom use, will be that "circus clown" song. You know, like when the car drives up and the clowns pile out, and then more and more of them, without end. Or maybe that will be popular for bedroom use. I'd like to stop thinking about it now.
1)
Unfortunately, every time you unzipped people would wander over to you expecting to find a food truck.