Hybrid Theory is the debut album by the American rock band Linkin Park, released on October 24, 2000 through Warner Bros. Records. The album was a commercial success, having been certified Diamond for sales of over 10 million units in the United States alone as of 2010, peaking at number two on the Billboard 200, and also reaching high positions on other charts worldwide. Recorded at NRG Recordings in North Hollywood, California, and produced by Don Gilmore, the album's lyrical themes deal with problems lead vocalist Chester Bennington experienced during his adolescence, including drug abuse and the constant fighting and divorce of his parents. Hybrid Theory takes it's title from the previous name of the band as well as the concept of music theory and combining different styles. Four singles were released from the album: "One Step Closer", "Crawling", "Paper cut", and "In the End", all of them being responsible for launching Linkin Park into mainstream popularity. While "In the End" was the most successful of the four, all of the singles in the album remain some of the band's most successful songs to date.