The guitar interface remains relatively unchanged in "World Tour". As with previous "Guitar Hero" titles, the guitar and bass player must hold down the correct fret button(s) on the controller while strumming in time with the notes as they scroll on-screen. One addition to the guitar gameplay is the ability to play notes while holding a sustained note. Additionally, the bass guitar player is required to play notes representing an open E string, which is shown on-screen as a solid line across their note track. To play these notes, the bass guitar player strums the controller without pressing any fret button keys. The drum interface is similar to the guitar's interface, with each on-screen note track equivalent to a colored drum head on the controller, with the bass drum indicated by a line across the note track. The drum player only needs to hit the correct drum pads simultaneously to the note gems to successfully play their track. There are also marked sections indicating drum fills wherein the player may play any notes they wish in a 'solo' to gain points. The vocal track requires the player to match the pitch of the notes in a manner similar to "Karaoke Revolution" to be successful. Special sections of each player's note track are marked with glowing notes, which, if completed successfully, builds up Star Power. Once enough Star Power is accumulated, it can be released via various means to double the band's current score multiplier. For guitar and bass, this is done by lifting the guitar controller vertically or (though not in bass) by pressing a button on the guitar face; for drums, by striking both cymbal pads on the controller at the same time; for vocals, by tapping the microphone or making a similarly quick sound. Star Power's use has been modified over previous "Guitar Hero" entries in that Star Power can now be accumulated even when Star Power is in use by successfully completing additional Star Power phrases, which extends the Star Power's duration.