The maximum number of players in Guitar Hero World Tour is 4.
World Tour expanded Guitar Hero beyond its earlier guitar-only format by supporting a complete virtual band: lead guitar, bass, drums, and vocals. Each role could be assigned to a separate player, allowing four people to perform together in local multiplayer and, on supported platforms and modes, online band play.
The number four refers to simultaneous band members, not the number of instruments included in every retail package. Players could also enjoy the game alone or with fewer than four people, with computer-controlled or unfilled parts depending on the mode. A common mix-up comes from confusing World Tour with earlier Guitar Hero games, which generally centered on one guitar player or smaller multiplayer arrangements. Guitar Hero 5 continued the four-person band structure, while Guitar Hero Live changed the series' format and focused primarily on a single guitarist.