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
Minecraft mods owners more control over their "Minecraft" environments. With the release of the alpha version, the first client-side mods began to appear; these added relatively simple things, like other textures or amendments to the in-game compass. Towards the end of 2010, new mods were released which featured more content than previous ones. "Minecraft" was now preparing to move into its beta development phase, and popular mods such as "IndustrialCraft", "Railcraft" and "BuildCraft" were first released to the public. As opposed to their predecessors, these mods had the potential to change the entire game instead of simply tweaking minor aspects of it.