Minecraft led to Persson becoming one of "Forbes" "World's Billionaires". "Minecraft"s music and sound effects were produced by German musician Daniel Rosenfeld, better known as C418. The background music in "Minecraft" is instrumental ambient music. On 4 March 2011, Rosenfeld released a soundtrack, titled "Minecraft – Volume Alpha"; it includes most of the tracks featured in "Minecraft", as well as other music not featured in the game. The video game blog Kotaku chose the music in "Minecraft" as one of the best video game soundtracks of 2011. On 9 November 2013, Rosenfeld released the second official soundtrack, titled "Minecraft – Volume
Markus Persson was released on 18 November 2011. Persson left his job as a game developer to work on "Minecraft" full-time until completion. In early 2011, Mojang AB sold the one millionth copy of the game, several months later their second, and several more their third. Mojang hired several new staff members for the "Minecraft" team, while Persson passed the lead developer role to Jens Bergensten. A version for Android and iOS, the "Pocket Edition", has also been released. An Xbox 360 edition of "Minecraft" was released on 9 May 2012. The Xbox edition features updates including a tutorial and skin packs.