More than a year ago, Activision revealed that the company was interested in branching its Guitar Hero franchise onto platforms such as the Nintendo DS. It's been a long wait, but the company has finally revealed the Guitar Hero game that will soon hit the dual-screen handheld later this year.

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The Nintendo DS version -- Guitar Hero: On Tour -- is in development at Vicarious Visions , the team best known for the Tony Hawk and Spider-Man series on the dual-screen handheld, as well as the Nintendo Wii conversion of Guitar Hero III: Legends of Rock released late last year. This portable version will feature the same rhythm-based "play to the music" gameplay of the big boys, and will even have its own peripheral to get the job done: Red Octane has developed what it's calling the Guitar Grip to give players the ability to finger chords in similar fashion as the console version's guitar peripheral.The Guitar Grip will plug into the Game Boy Advance slot at the bottom of the Nintendo DS system. Players put their hand through the strap of the Guitar Grip for a firm hold on the system, and then position the system in its vertical book form. The peripheral has a storage area for a specially designed stlyus pick, which is used to strum the guitar strings on the touch-screen. As the notes slide down the screen, players strum the strings while pressing the corresponding fret buttons, all to the rhythm of the song that's being played. According to the video released by Activision, the microphone comes into play during songs -- we're guessing it'll be used as control to activate Guitar Hero's "Star Power" mode to increase the points multiplier.The idea for the peripheral came during the prototyping phase of getting Guitar Hero working on the Nintendo DS. "We began prototyping ideas for Guitar Hero on DS in early 2007," said Karthik Bala, CEO of Vicarious Visions. "We quite frankly didn't know whether it would be possible to bring the core essence of the franchise to handheld and have it actually work. It was 20-something gameplay prototypes that were built, all trying different mechanics and uses of the hardware. Some were pretty cool, others were total disasters!"At some point, we hit upon the idea of creating a peripheral that would have the fret buttons plugging into the GBA slot of the DS," he recalled. "We ripped apart an old GBA cartridge and did some electronics work on it to rig up a prototype device. As awkward and crude as that prototype was, that's when we knew we were onto something. We figured that attaching a full-size guitar or even a mini-guitar would be too awkward to play on the road, hence the design of the more compact Guitar Grip, which gives you the tactile sense of the fret buttons, with the touch screen depicting the strings of the guitar."Activision's hasn't released all details regarding Guitar Hero: On Tour, but we do know that the Nintendo DS version will feature similar single player Career Mode progression as the console game. On Tour will contain a line-up of more than 20 licensed songs from bands as Nirvana, OK Go, and No Doubt; Activision will most certainly reveal the full list of bands and songs as we get closer to the game's summer release date. Players will be able to pick from six different guitarists to represent them in-game -- while four guitarists have been in Guitar Hero before, two of the characters have been designed exclusively for the Nintendo DS game. As they get through career mode, they'll unlock venues as well as outfits to deck out their chosen persona.Along with the single player campaign, Guitar Hero: On Tour will also support multiplayer. The game will feature both co-op as well as competitive two player options using the local wireless functions of the Nintendo DS system. The game's battle mode will feature similar gameplay as the mode created in Guitar Hero III, with power-ups created specifically for Guitar Hero: On Tour. For example, players can activate power-ups that'll send raving fans to the other screen, and the opponent will have to sign autographs on the touchscreen to get rid of them. Or out-of-control pyrotechnics will be set ablaze, and players will have to blow them out using the Nintendo DS microphone.Activision has yet to announce a price-point or a release date, but the company did reveal that it's shooting to ship Guitar Hero: On Tour this summer. While console games have been branded with ESRB's T for Teen rating mostly due to song lyrics, Guitar Hero: On Tour will be rated E10.