When a game is as popular as Guitar Hero World Tour, you rush to market by offering it on as many platforms as you can as fast as you can, including the mobile phone. On Thursday, the mobile version of Guitar Hero World Tour became available on AT&T phones.

On the PlayStation, Wii, and Xbox, this fourth generation of Guitar Hero counters Rock Band’s drum and vocal tracks, which themselves had one-upped Guitar Hero’s original stringed instrument. Vocals aren’t practical for the mobile version–which still rocks, by

the way–but a drum track is. Activision and game-maker Hands-On Mobile have introduced a drum choice for every song.

Guitar Hero World Tour Mobile comes with fifteen new songs for guitar and drums, and which uses the phone’s keypad buttons instead of guitar frets. The kick-drum is played using the bottom row of keys (7, 8, 9), which is represented in the game by a horizontal purple line that floats at you along with the notes.

According to CNet.com: AT&T will be the first to carrier Guitar Hero World Tour Mobile, but by the end of November the game will also be available on Sprint (11/17), Verizon (11/25), and shortly after that on T-Mobile, Alltel, and USCC. The game will work on Java and BREW phones this month, BlackBerry phones next month, followed by Windows Mobile and Google Android.