Truean, just to make sure I understand - how is what you're proposing any different from what youTube/VEVO does, right now? Because really, the youtube/pandora model, with streaming+commercials, is honestly the closest you'll probably get. (And copying those streams is pretty common, so even that's mostly a result of people just not bothering to get rid of the ads rather than being unable to)
Because you know what would happen if people started adding that sort of crap to songs? Oh, look at that, someone removed it and now everyone is pirating it from another source instead of getting the legitimate version because they don't want to have to listen to an ad every two and a half minutes.
So yes, it is completely and utterly impossible, unless you somehow manage to eradicate all operating systems other than RIIA-approved ones.
Basically, this - an application could do it, perhaps, but an audio file? No. And the application can only do it if it's RUNNING, and anyone editing a file like this wouldn't be running it. You'd have to have some sort of "security application" constantly running on the computer insuring the file wasn't tampered with, and there are quite a few users who will know how to turn it off sooner or later. And once that's been done, they will distribute the unlocked version and you're back at square one, except now people have additional incentives to avoid the official one. This has been attempted dozens of times, and it all ends the exact same way. And the fact is, this stuff is dangerous - it's usually full of security holes, won't work one one or more OSes, and provides negligible protection - studies have shown the only people willing to buy into it are those ALREADY willing to buy the music anyways.
You're much better off coming up with a reason for people to pay for the official version, or otherwise people will just do what they want. (See: Steam, Youtube, Hulu, Netflix) If you're not adding value, people will bypass whatever protections you put in place. If you ARE adding value, they might put up with it, but most studies have shown the "protections" are provided by the added value, not the crappy DRM.
One reason it hasn't taken off for music is in part because some of the music companies don't want it to. They think it would make people stop buying CDs or some crap. Remember, these are the same companies that were officially opposed to the iTunes model for a whole bunch of years before basically being forced into it.