Guitar Hero is back — and this time, the songs are free in the cloud

Activision built a multibillion-dollar business with Guitar Hero earlier this decade — and then saw it all collapse as gamers tired of fake guitars. Now, like an aging rock star, it’s trying for a comeback.

This time, the company is banking on a combination of innovation, social networking, and a fresh take that turns the camera around, pointing your attention not at the rest of your band but at the audience that’s watching you. This is a modern Guitar Hero, with a new guitar and a new way of visualizing the world and feeling the audience react to your performance. If it works, it could revive the music games genre that generated more than $2 billion for Activision.