He studied vocals at the Pop/Jazz Conservatory in Helsinki, briefly singing for an amateur cover band named Filthy Asses. In summer of 1994 he applied to Stratovarius, who were looking for a singer at the time, and was accepted. His arrival corresponds closely with the band's rise to international fame. The first album he recorded with the band was Fourth Dimension, in 1995. Stratovarius has then become a top name in the European heavy metal scene, recording eleven more albums and performing in numerous notable rock festivals.
In late 2003, he split from Stratovarius after intra-band disagreements, notably with guitarist Timo Tolkki. After much turmoil throughout 2004, he rejoined the band in January 2005, recorded the album Stratovarius, and performed live on a tour that covered North America, South America, Europe and Asia.
In 2002 he started his solo project, called Kotipelto. So far he has released three albums: Waiting For The Dawn, Coldness and the last one, released 20th April 2007, Serenity. He performed with Rod Kresp (Lead singer) of The Vault in Brazil.
Aside from Stratovarius and Kotipelto, he has also provided backing vocals to Sonata Arctica's Silence album, and lead vocals for the song Out of the White Hole, on Ayreon's 2000 release Universal Migrator Part 2: Flight of the Migrator.