Question: Tuomas Lauri Johannes Holopainen, is a Finnish songwriter, multi-instrumentalist musician (but mainly keyboardist) and record producer, best known as the founder, leader, keyboardist and songwriter of symphonic metal band Nightwish, formed in which year? 

Context articles: Nightwish discography
Marco Hietala
Imaginaerum
The First Tour of the Angels
Music Inspired by the Life and Times of Scrooge
Imaginaerum (film)
End of Innocence (Nightwish)
Nightwish
Tuomas Holopainen
Oceanborn Europe Tour

The discography of the Finnish symphonic metal band Nightwish consists of eight studio albums, one extended play, four live albums, seven compilations, thirteen music videos and twenty one singles.
 The band was formed in 1996 by songwriter and keyboardist Tuomas Holopainen, guitarist Emppu Vuorinen, and former vocalist Tarja Turunen; Nightwish's current line-up has six members although Turunen has been replaced by Anette Olzon, and the original bassist, Sami Vänskä, has been replaced by Marco Hietala, who also took over the male vocalist part.
 Olzon left the band in 2012 and was replaced by Floor Jansen.
Marko Tapani "Marco" Hietala (born 14 January 1966) is a Finnish heavy metal vocalist, bass guitarist and songwriter.
 Internationally, he is most known as the current bass guitarist, male vocalist and secondary composer to Tuomas Holopainen, of the symphonic metal band Nightwish.
 He is also the vocalist and bassist as well as composer and lyricist for the heavy metal band Tarot.
Imaginaerum is the seventh studio album by Finnish symphonic metal band Nightwish.
 According to Nightwish songwriter Tuomas Holopainen, the album is a concept album that tells the story of an old composer who is reminiscing of his youth on his deathbed.
 The album was produced alongside the movie of the same name, directed by Stobe Harju, who previously directed Nightwish's "The Islander" music video, and the album and the film share the same themes and general story.
 It is their second and last album with vocalist Anette Olzon.
The First Tour of the Angels was a concert tour by Finnish symphonic power metal band Nightwish from December 31, 1997, to November 13, 1998.
 Nightwish played only 8 gigs since Jukka Nevalainen and Emppu Vuorinen were waylaid by their mandatory military draft and Tarja Turunen had not finished her studies.
 The male vocals in "Beauty and the Beast", "The Carpenter" and "Astral Romance" were sung by Tuomas Holopainen, beside Tarja.
 The band was supported by bassist Samppa Hirvonen and the keyboardist Marianna Pellinen during the tour; in 1998, Samppa was replaced by Sami Vänskä.
 There is a bootleg of the Helsinki gig called Live at The Tavastia.
Music Inspired by the Life and Times of Scrooge is the first solo album by Finnish songwriter and keyboardist Tuomas Holopainen, best known for his work in the symphonic metal band Nightwish.
 It was based on cartoonist Don Rosa's "The Life and Times of Scrooge McDuck", a graphic novel which featured the Carl Barks Disney comics character of the same name.
 Rosa contributed the cover artwork.
 The first single, "A Lifetime of Adventure" was released on February 5, 2014 along with a music video directed by Ville Lipiäinen.
Imaginaerum (also promoted as Imaginaerum by Nightwish) is a 2012 Finnish-Canadian musical fantasy film co-written and directed by Stobe Harju.
 It was developed with and features music from Finnish symphonic metal band Nightwish's seventh studio album of the same name; Nightwish's keyboardist and songwriter Tuomas Holopainen co-wrote the film.
 "Imaginaerum", which is produced by Markus Selin from Solar Films Inc. along with Nightwish, is the feature film debut of Stobe Harju.
End of Innocence is the second official DVD release of Finnish symphonic metal band Nightwish.
 The DVD features numerous clips of the band performing livetracks, including a recording of the band performing one of their first songs; "Beauty and the Beast", with bassist Marco Hietala performing the male vocal part (in the past this part was performed by Tuomas Holopainen or Tony Kakko, from Sonata Arctica).
Nightwish is a symphonic metal band from Kitee, Finland.
 The band was formed in 1996 by lead songwriter and keyboardist Tuomas Holopainen, guitarist Emppu Vuorinen, and former lead singer Tarja Turunen.
 The band soon picked up drummer Jukka Nevalainen, and then bassist Sami Vänskä after the release of their debut album, "Angels Fall First" (1997).
 In 2001, Vänskä was replaced by Marco Hietala, who also took over the male vocalist role previously filled by Holopainen or guest singers.
Tuomas Lauri Johannes Holopainen (born 25 December 1976) is a Finnish songwriter, multi-instrumentalist musician (but mainly keyboardist) and record producer, best known as the founder, leader, keyboardist and songwriter of symphonic metal band Nightwish.
 He has also studied jazz and classical styles, but prefers to be influenced by harmonic film music.
Oceanborn Europe Tour was a concert tour by Finnish symphonic metal band Nightwish from November 12 to December 12, 1999.
 The tour is notable for featuring the band's first European concerts.
 Oceanborn Europe Tour followed a Finnish leg with 33 shows, the Summer of Wilderness.
 In this tour, Nightwish played beside German heavy metal band Rage, and Nightwish was occasionally supported by Finnish singer Tapio Wilska, singing in the songs "The Pharaoh Sails to Orion" and "Devil and the Deep Dark Ocean"; Tuomas Holopainen performed "Beauty and the Beast" and "Astral Romance" beside Nightwish's frontwoman, Tarja Turunen.