But let’s get back to this business of digital downloads lacking any physical presence. This idea — the notion that music, now, is just math, just information floating about the ether — turns out to be of some importance. Apple has sold us 5 billion songs, but do we really own that music?

Not most of it. People seem dimly aware of this, but it bears repeating: The vast majority of the songs we’ve bought through iTunes are gummed up with FairPlay, a digital-rights management scheme that Apple cooked up years ago to satisfy the recording industry.

FairPlay works like this: Every time you move your music to a new computer, iTunes calls up Apple’s servers to request “authorization” to play the tracks. The trick works fine, usually, as long as you are abiding by Apple’s restrictions.

But what if Apple’s servers go down? Indeed, what if, at some point in the future, there is no Apple, or iTunes? Then you’re stuck. That’s the gamble of copy protection: Because your songs must phone home, they’re not your songs, not really.

Why am I mentioning this now, raining on Apple’s 5 billion parade? Because the concern is not hypothetical. Exhibit A: Customers of Microsoft’s music store, which went online in 2004, and unceremoniously came down in 2006, are smarting over just this sort of thing.

In April, the company sent former customers an ominous notice. Microsoft had decided to shut down its authorization servers, meaning that people’s songs would break after Aug. 31. The company recommended that they laboriously burn each of their tracks to audio CDs (a process that results in lower-quality digital tracks).

After an outcry, Microsoft announced yesterday that it has reconsidered its decision.

Now customers will have until 2011 to enjoy the music they purchased. But MSN customers are living on borrowed time. One day, Microsoft will power down its servers, and when songs call out for permission, they’ll hear no response, and they won’t play.

But this is true of all DRM-protected music, not just Microsoft’s. ITunes and Apple don’t look vulnerable now, but the tech industry changes fast. One day a company or a product seems invincible, the next it’s curtains.

There’s no reason to gamble: When you’re looking for digital downloads, check out Amazon’s superb MP3 store first. And if you must buy from Apple, make sure your track is labeled “iTunes Plus,” which is Apple’s way of saying it’s free of copy protection. Your music shouldn’t have to ask for permission.

Here’s the happier thing: The Spore Creator, the first bit of public code from the much-anticipated video game Spore, is now available for download.

Spore, of course, is Will Wright’s next video game. You may remember Will Wright from his previous hits — SimCity and The Sims, say?

Spore, which Wright’s fans have been salivating over for years, has been called Sim Everything, or Sim Evolution: It lets you watch and guide the development of a species from the lowest scale — the cellular level — all the way to the largest, when your species acquires advanced intelligence and can hop through outer space (in other words, it becomes Snoop Dogg).

Spore will go on sale in September. But today Maxis, Wright’s game company, is releasing one portion of the game, the Creature Creator, for everyone for free.

Think of this as a pre-release demo, but with a twist. Will Wright calls Spore a “massively single-player” game, a clever way of saying that you’ll play the game by yourself, but it’ll be thoroughly social, populated by stuff that other people have created in their single-player games.

Maxis hopes that during the next few months, people all over the world will download the Creature Creator and build enough interesting Spore animals to fill the full game when it’s released.

Last week, Maxis invited the tech press over to its office to test out the Creature Creator. I’ve been playing it often since then: The Creature Creator is delicious, addictive fun.

You’ll grasp Spore’s intuitive interface in seconds, and after that your imagination takes reign. Pull legs, arms, feet, mouths, and various other animal parts onto your creature, resize and rotate and stretch and bend every bit of it, and then paint the whole thing to your delight.

Even though you can’t yet do anything with the creatures you create — there’s only a Test Drive mode, which lets your character walk, jump, and perform a few antics within a small circle of Spore space — just building them is enough to keep you occupied for weeks.

And then there’s the social part: You can share each of your creatures in the Sporepedia, an online, public repository of Sporey things. There, people can rate and comment on your animals, and folks can also select them to populate their Spore games.

The game’s also got built-in YouTube sharing — down below, I’ve posted a clip of Strange Fish, the Spore creature I made last night.

Here are screenshots of the creation process. Or try your own: Download The Spore Creature Creator, available for Mac or PC, here.

Every creature starts with a body. For this one, I went long and thin:

Then, a single back leg:

And how about two in the front?

Then, a face:

Eyes, bat ears:

Feet, hands:

Dino-webbing on its back, plus a paint job:

And another paint job:

Easy, huh? Intelligent design has never been so fun. And now, here’s a Spore-created YouTube clip of my creature (one knock on Spore: the quality of these videos needs upgrading):

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I raved about Spore in my video for Current TV this week.