The group later expanded to a six piece when they added,, and Mark Wakefield to the line-up. Mark Wakefield was later changed by lead vocalist. After facing numerous rejections from several major, Linkin Park turned to Jeff Blue for additional help. After failing to catch on three previous reviews,, now the vice president of Warner Bros. Records, helped the band sign a deal with the company in 1999. The band released its breakthrough album,, the following year.
The album produced four singles, ', ', ' and '. The album included a total of twelve songs in addition with two special edition tracks available in Japan. Later in 2002 the band released a, which would include works from Hybrid Theory and non-album tracks.