From that point on, the Guitar Hero series became more focused on full band gameplay. Neversoft introduced more instruments in the fourth main series instalment, Guitar Hero World Tour, likely in an attempt to compete with Rock Band, which had released not too long after Guitar Hero III.
The first Guitar Hero game that Neversoft created was Guitar Hero III: Legends of Rock, and it was the most successful game in the series, by far. Activision chose a compay called Neversoft to develop the next entry in the Guitar Hero series. Harmonix and RedOctane also developed a spin-off game titled Guitar Hero Encore: Rocks the 80s, but eventually RedOctane was bought out by Activision, and Harmonix by MTV. The first game was extremely successful, prompting sequel, Guitar Hero II, a year later.
They partnered with rhythm game developer Harmonix, and released Guitar Hero in November of 2005.
This game had only been released in Japan, and RedOctane was confident they could make a very similar game, with a comparable Guitar controller, in the west. Sometime in the early to mid 2000s, hardware developer RedOctane discovered a rhythm game made by Konami called Guitar Freaks, which used a Guitar shaped controller and featured a rock and roll based soundtrack.