You know, when Napster announced its subscription music plan, I never gave it a second look. Not because I assumed it wouldn’t work with my Linux box or Katie’s Mac, but for one simple reason:

No matter how many songs you “buy” on the plan, once your subscription lapses, they’re all gone.

Want to stop paying $15/mo? Say goodbye to your music.

Napster goes out of business? Say goodbye to your music.

On the other hand, suppose I’ve bought a bunch of songs from iTunes at 99ยข each, and I decide I don’t want to buy any more from them? No problem. If the marketplace changes two years from now and Apple decides to abandon the iTunes music store, I can still listen to songs I bought from them.

Amazingly, some people still need this explained to them. John Gruber of Daring Fireball writes, “I thought this was obvious, but, judging by my email, there seems to be a fair amount of confusion…” Forget the math, do the logic first!

There is one flaw in Gruber’s logic regarding CDs vs. subscription music: while I expect CDs will be playable over the next decade or two, eventually they will go the way of vinyl records. However, if I were to bet, I’d expect my CD collection will be playable long after Napster To Go has, shall we say, gone.

So Apple is ticked off at Real’s reverse-engineering to let people buy music from Real and play it on an iPod. Apple has threatened DMCA sanctions and all but promised to deliberately break it in the next software update.

Excuse me? In general I like Apple, but their insistence on locking the iPod to iTunes and iTunes alone is short-sighted. When people hacked up a way to use an iPod on Windows, they first licensed the software, then wrote iTunes for Windows. iPod sales have tripled to the point where they may soon outsell Macintoshes. This could never have happened if Apple had kept the iPod Mac-specific.

I’m reminded of the many times Microsoft has altered its file-sharing protocol to break compatibility with Samba, the package that allows Linux, BSD, and now Mac OS X to connect to Windows networks.

The classic analogy is getting a car that can only run on certain roads. So someone’s found a way to let the iPod drive some different roads. But Apple still sells as many iPods. They might even sell more (as when it gained Windows compatibility). Why the accusations of hacking, why the legal threats, and why the determination to keep the iPod locked to their own roads?

On the drive to work this morning, I noticed that KCRW was playing Pachelbel’s Canon in D in the background of their traffic report. As usual, the orchestration added several layers over the course of the report…

…and then, just as they were finishing, the drum track started.