Founded and led the symphonic metal band Nightwish. He was heavily influenced by harmonic film music.
He attended a music college for 11 years, where he studied clarinet, tenor saxophone, piano, and music theory.
He co-wrote the Nightwish film Imaginaerum, which was released in 2012.
His older brother, Petri, became an autopsy assistant.
He was a devout fan of Disney, Dragonlance, and J.R.R. Tolkien.