Rock Band 3 allows for 1–7 players, either locally or through online game services, to use various instrument controllers to accurately simulate the playing of music. In addition to supporting the four Basic instrument controllers from previous Rock Band games (lead guitar, bass guitar, drums and vocals), Rock Band 3 adds support for two additional microphones for singers to provide backup vocal harmonies (previously found in The Beatles: Rock Band and Green Day: Rock Band), an electric keyboard as a new instrument (or any MIDI-compatible keyboard), plus support for a specially made 102-button MIDI bass, and an actual Squier guitar by Fender. Support for MIDI compatible electronic drum kits as well.
Prior to a song, each band member selects from one of four difficulty levels, Easy, Medium, Hard, and Expert, which influence the number and rate that notes appear on the note track; they also can select the Pro mode for real guitar, bass, keyboards, and drums. As the band performs, they score points. Each player can build up a multiplier by hitting consecutive notes correctly, which increases how many points each note is worth, but the multiplier is set back to 1× if a note is missed. After successfully completing a song, the performance of each player and the band as a whole is rated on a 5-star scale. The best performance by a player for each song in the player's library is tracked separately based on instrument, Basic or Pro mode, and difficulty, then is used to provide and compare leaderboard statistics at the end of the song.[4]