Guitar Hero, Rock Band, and Rock Revolution all translate loosely into buy our accessories. These games started off somewhat simple, only requiring the user to buy a guitar accessory, or two if they had friends. Enter Rock Band. Let's mix Guitar Hero, Karaoke Revolution and throw in an accessory of our own, the drums.
Now these games all have their own accessories, and they're cross platform as well. The worst part for consumers, and the an ingenious marketing strategy is to make these accessories not 100% compatible with each other. This is slowly changing; they are seemingly trying to make the stuff more compatible. Producing the game discs is pretty much free, and all profit, so why not sell as many games as you can? Joystiq published a ridiculous big chart to help you know whether or not you need to buy new guitars and drums for your new music game.
Looking for a version for the computer? Into Jesus? Then Guitar Praise is for you! Featuring songs like: Made to Worship by Chris Tomlin, Jesus Freak by dc Talk, and All The Earth Will Sing Your Praises by Paul Baloche. I'm sure there are other non-Jesus versions, but this one seemed noteworthy.
I'm probably the only person on this site who is not into these games at all. Richard even wrote a bit on Will and Beyond about a guy becoming famous from Guitar Hero. I don't like the guitar much, nor the drums, and I abhor singing. My only guilty exception to this musical genre hating is DDR; for some reason, I love it so.
Image: The Gamer Gene