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 sets based on "Minecraft". Two more sets based on the Nether and village areas of the game were released on 1 September 2013. A fourth Micro World set, the End, was released in June 2014. Six more, larger Lego minifigure scale, sets became available November 2014. Mojang collaborates with Jinx, an online game merchandise store, to sell "Minecraft" merchandise, such as clothing, foam pickaxes, and toys of creatures in the game. By May 2012, over 1 million dollars were made from "Minecraft" merchandise sales. T-shirts and socks were the most popular products. In March 2013 Mojang signed a deal with