Question: Who sings for their main band, Anette Olzon or Brian Welch?

Context paragraphs:
Crimson Skies (album): Crimson Skies is a 2006 studio album by the Swedish metal band Cloudscape.  It is the band's second studio album.  On June 9, 2006 Cloudscape performed at the Sweden Rock Festival to promote "Crimson Skies" followed by other appearances at clubs and festivals around in Europe.  A performance of the song "Demon Tears" was filmed and released as music video to promote the album.  On the song "Will We Remain", singer Anette Olzon appeared as guest on vocals.

Brian Welch: Brian Philip Welch (born June 19, 1970), better known by the stage name Head, is an American musician, singer and songwriter best known as one of the guitarists and co-founder of the nu metal band Korn and his solo project Love and Death.  Along with fellow Korn guitarist James "Munky" Shaffer, Welch helped develop Korn's distinctive sound, a mix of sirenlike shards of dissonant guitar that mimicked a turntablist's various effects and rumbling down-tuned riffing, that defined the nu metal aesthetic beginning in the mid-'90s.

Changes (Alyson Avenue album): Changes is the third album by Swedish AOR/rock band Alyson Avenue with new vocalist Arabella Vitanc.  Alyson Avenue released their third album "Changes" through Avenue of Allies.  The record was co-produced by band members and Chris Laney (Crazy Lixx, H.E.A.T., Brian Robertson) and includes guest appearances by Anette Olzon (Ex-Nightwish, Ex-Alyson Avenue), Michael Bormann (Ex-Jaded Heart, Charade, BISS), Rob Marcello (Danger Danger, Marcello - Vestry), Fredrik Bergh, (Street Talk, Bloodbound), Tommy Stråhle and Mike Andersson (Cloudscape, Planet Alliance).

Dark Passion Play World Tour: Dark Passion Play World Tour was the fourth world tour by Finnish symphonic metal band Nightwish, taking place from 2007 to 2009 in support of their sixth studio album, "Dark Passion Play", released by Nuclear Blast on September 26, 2007; it was the first tour with former frontwoman Anette Olzon, who joined the band in 2006, after Tarja Turunen's dismissal on October 21, 2005.  During this tour, the band played for the first time in Israel, China, Hong Kong, Lithuania, Luxembourg, Republic of Ireland, Serbia and Croatia.

Dark Passion Play: Dark Passion Play is the sixth studio album by Finnish symphonic metal band Nightwish, released on 26 September 2007 in Finland, 28 September in Europe and 2 October 2007 in the United States.  It is the first album without original vocalist Tarja Turunen, who was dismissed in 2005, as well as the first album involving future member Troy Donockley on uilleann pipes and tin whistle.  It is the first of only two albums with vocalist Anette Olzon, who was eventually dismissed in 2012 after the release of the band's subsequent album, "Imaginaerum".  Tuomas Holopainen has referred to it as the "album that saved his life".

Omega (Alyson Avenue album): Omega is the second studio album by Alyson Avenue, and the band's final album with lead vocalist Anette Olzon.  It was released on May 6, 2004, by the label AOR Heaven.  It was re-released on July 14, 2009, along with their first album "Presence of Mind".  Omega II comes with five exclusive bonus tracks with Anette Olzon, and their first single "I Am (Your Pleasuremaker)".

Showtime, Storytime: Showtime, Storytime is a video release, released as a double Blu-ray, DVD and CD from Finnish symphonic metal band Nightwish.  Nuclear Blast recorded their live performance at Wacken Open Air in Wacken, Germany on August 3, 2013.  "Showtime, Storytime" is the first Nightwish production to feature Floor Jansen on vocals.  She initially replaced previous vocalist Anette Olzon during their North America tour leg, and on October 9, 2013, it was revealed that she would become an official band member, along with Troy Donockley.  The running time of the concert is 1 hour and 38 minutes.  The album also contains a 120-minute documentary about the first days of Jansen in the band, still as an only live member, and her process of adaptation in the band, called "Please Learn the Setlist in 48 Hours".

Nightwish discography: 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.

Anette Olzon: Anette Ingegerd Olsson (born 21 June 1971), known by the stage name Anette Olzon, is a Swedish singer, best known as the lead vocalist of Finnish symphonic metal band Nightwish from 2007 to 2012.  She is also the former vocalist of Swedish classic rock band Alyson Avenue.

Eva (Nightwish song): "Eva " is the first single of Finnish symphonic metal band Nightwish's sixth studio album "Dark Passion Play".  It was the first release to feature the band's new singer, Anette Olzon, following Tarja Turunen's departure in 2005.

Supporting paragraphs: Brian Welch Anette Olzon
Answer: Brian Philip Welch