A series of rhythm games for home video game consoles produced by Harmonix, Rock Band is a series of rhythm games. The main Rock Band games use game controllers modelled after musical instruments and microphones to perform the lead guitar, bass guitar, keyboard, drums, and vocal parts of numerous licenced songs across a wide range of genres, but primarily focusing on rock music by matching scrolling musical notes patterns shown on the screen. Pro instruments, which need specialised controllers that more accurately resemble the playing of actual instruments, may be used in certain games. When a player hits all the notes correctly, they get points, but if they miss too many, they lose points and the song is a failure. There are various game modes in the series, and most of them enable local and internet multiplayer for up to four players.
Music video game publisher MTV Games purchased Harmonix in 2007 when Red Octane was acquired by Activision to continue the Guitar Hero franchise. MTV Games functioned as publisher and maker of instrument controllers for Rock Band, with distribution handled by Electronic Arts. For reasons that are yet unclear, both Guitar Hero and Rock Band saw a decline in sales in 2009. Harmonix's investors purchased Viacom, making the business independent, allowing them to have greater control over the series' future. In 2010, Harmonix was sold to Mad Catz for the publishing and production of instrumentation controllers. Rock Band 3 downloadable material (DLC) was discontinued by Harmonix in 2013, however the company announced that they were considering their options for the series when the next generation consoles arrived. Harmonix launched Rock Band 4 for the new platforms in 2015, after the launch of the PlayStation 4 and Xbox One. The new instrument controllers were first produced by Mad Catz. As a result of the game's poor financial performance, Mad Catz had to file for bankruptcy, and Harmonix was forced to outsource instrument controller manufacturing to Performance Designed Products (PDP).
A total of eight Rock Band games have been released, including The Beatles: Rock Band, as well as two more band-specific spin-offs and Track Packs. As of May 2020, Harmonix has continued to maintain Rock Band via a permanent DLC model, with regular releases of new songs on a weekly basis and the possibility for users to integrate music from past games into current ones. The Rock Band Network was a Harmonix service that allowed bands and labels to publish their songs as Rock Band tracks that players could buy; at its peak, over 4,000 tracks from 1,200 artists were accessible for Rock Band users. This service has now been terminated.
By the end of 2009, more than $1 billion had been earned from the sale of more than 13 million copies of Rock Band games. By the end of 2009, more than 130 million downloaded songs had been purchased.