Rock Band 4 is a 2015 music video game developed by Harmonix. Rock Band 4 allows players to simulate the playing of music across many different decades and genres using instrument controllers that mimic playing lead and bass guitar, drums, and vocals. As the fourth main installment in the Rock Band franchise, it was released for PlayStation 4 and Xbox One on October 6, 2015. Mad Catz, who also developed new instrument controllers for the game, marketed and distributed the title worldwide. The game shipped with more than sixty licensed songs; additional songs are available as downloadable content, which includes a library of over 2000 existing songs from prior installments.