How Guitar Hero Works

To create a music-based video game with mass appeal, you need a variety of songs from multiple eras. For that reason, the Guitar Hero set list is loaded with older tracks, such as "Welcome to the Jungle" by Guns N' Roses and more recent hits including "When You Were Young" by the Killers.

According to Jeff Matsushita, the executive producer of RedOctane, the songs for "Guitar Hero III: Legends of Rock" had to fulfill the criteria of being legendary and enjoyable to play [source: McBride]. After nailing down the desired set list, California sound company WaveGroup rerecorded some tracks if Guitar Hero didn't purchase a music license to use a master version. By combing through artist interviews and learning how the originals were produced, WaveGroup strived to make the covers authentic and fun for the players.

Next, the Neversoft development group's note tracking team translated the songs into digital maps. The team extracted the specific guitar or bass notes that the players must hit and plotted where those notes go on the actual game screen. Note trackers also cue animations and light shows to correspond with notes. That's what makes Lars Umlaut raise his guitar during a particularly awesome solo, for instance.

These notes are coded to interact with the Gibson guitar-shaped controller and score your performance. This coding reacts to the combination of the fret button and the strum bar. The fret buttons and strum bar electronically trigger the appropriate animation and sound effects when correctly activated. For instance, if you press down the green fret button and hit the strum bar as a green gem hits the target line, the gem bursts into a flame, and you hear the right note in the song.

While the fret button makes the note selection, the strum bar regulates the timing that the sound effects and animations register on the display screen. That's why hitting the correct fret button but strumming at the wrong time means a missed note.To make that happen, the strum bar is spring loaded so that when you hit it, a lever inside the strum bar strikes an electric switch. That switch sends an electrical message to the game's software that the strum bar has been activated. At the same time, the fret buttons also communicate with the software when you press them down, much like a button on a regular video game controller.

Remember how you can tilt your controller up to activate star power? Your controller contains sensors that react to the accelerated motion and change in gravity when you raise the controller vertically from its horizontal resting position.

The whammy bar, according to a patent from Harmonix, which was the original Guitar Hero developer, operates similarly to a joystick. Physical movement stimulates an electronic switch that signals the software and results in the reverb, if your timing is correct [source: Schmidt et al]. For more specific information on joystick technology, read How Joysticks Work.

As you see, it's taken a lot of work to go from a number of song selections to a video game. Read on to learn the history behind these Guitar Hero innovations.