At the beginning he was a vocalist in a grunge band called Grey Daze. He left Grey Daze in 1998. After that, the vice president of A&R at Zomba Music in Los Angeles, offered Bennington an audition with Linkin Park. Bennington went to California and joined the band. Their name was “Hybrid Theory”. The other vocalist was Mike Shinoda. After some rejections, Jeff Blue operated to help the band sign with Warner Bros. Records.