SOMETIME AFTER the 2008 launch of Rock Band 2, developer Harmonix realized a very important fact about rhythm games: The most important part of a good rhythm game is not music.

Sure, you need music, but the massive success of the genre proves that almost any kind will do: country, hiphop, Japanese pop—as long as it has a beat, it works.

Harmonix knows the key to the rhythm genre is social interaction. Stop by Ground Kontrol on a Tuesday for one of their Rock Band Tuesdays nights, and you'll see what I mean. The life of a rock star is many things—dirty, glamorous, sensationalized—but if there's one thing it's not, it's lonely.

Rock Band 3 is the best rhythm game yet because it wholeheartedly embraces this social ethos. The series has always had multiplayer options—the main tenet of the first game was how cool it was to be able to play in a four-person band—but RB3 makes everything social. Even playing solo is an exercise in managing faux band members, promoting yourself to others, and, of course, rocking along with (real or simulated) pals.

That's not to say that RB3 entirely ditches its roots. The 80-plus songs on the game's disc are easily the series' most esoteric to date, yet they perfectly complement the series' foundations. Add that to the already gigantic Rock Band Store, and the tunes available from other Rock Band releases, and you have more than 2,000 songs to choose from. And with more being released every week, you won't run out of content. Ever.

Rounding out the package are a handful of neat extras, like the ability to create and share your own setlists online and expanded customization options for your characters and band. They're small additions, but like everything in RB3, you can tell that there's real thought going into the product.

It's funny that comparing the latest Guitar Hero and Rock Band releases feels like comparing a stodgy corporate cash grab and a soulful, independent work of creative expression. Given how much cash is involved, that idea is totally laughable, but when has rock been about anything other than image?