In addition to developing new songs for purchase following the release of Rock Band 4, Harmonix was also working to ensure that as much of its existing library of downloadable songs would be compatible with the game upon its release as possible 1,500 songs were available at launch. Main article: List of downloadable songs for the Rock Band series Harmonix allowed for fans to request songs to be included in the game, and tried to include the most-requested songs. Rigopulos said of the main soundtrack that 'The budget that we’ve allocated for the title supports a top-tier soundtrack'. ' Metropolis-Part I: 'The Miracle and the Sleeper'' Rock Band 4 is shipped with 65 songs on disc. Harmonix plans to continue to develop additional downloadable content for the game. Though the game includes new features such as freestyle guitar solos and improved drum fills, Harmonix has worked to assure that at least 1,700 of the songs in its downloadable content library from past Rock Band games are compatible with Rock Band 4 and that players who have already bought songs on the previous iterations do not have to repurchase the songs in the newer game as long as they stay within the same console library. Rock Band 4 ships with 65 songs on the disc, spanning rock music and other genres from the 1960s to the 2010s. The release of Rock Band 4 was prompted by several factors, including the market penetration of the eighth generation consoles PlayStation 4 and Xbox One, a stronger internal vision for what Rock Band 4 should be within Harmonix, and continued support from fans of the series. Following the over-saturation of the rhythm game market in 2009, weak sales of Rock Band 3 led Harmonix to put the series on hiatus, though the company continued to provide downloadable content through 2013. The game was released in October 2015, following a five-year hiatus from the release of Rock Band 3. Rock Band 4 is the fourth main installment in the rhythm game series, Rock Band, developed by Harmonix.

Rock Band 4 features tracks by the band U2, the first time songs from the group have been included in a rhythm game.

Free download rock band 4 wii