Question: Are Masatoshi Ono and Anette Olzon both singers ?

Context articles: October &amp; April
Eva (Nightwish song)
Dark Passion Play
Anette Olzon
Masatoshi Ono
Changes (Alyson Avenue album)
Omega (Alyson Avenue album)
Nightwish discography
Dark Passion Play World Tour
List of Dark Passion Play editions

"October & April" is a song by the Finnish rock band The Rasmus, featuring Anette Olzon from Nightwish.
"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.
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".
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.
Masatoshi Ono (小野正利 , Ono Masatoshi , born January 29, 1967 in Adachi, Tokyo, Japan) , also known as Sho, is a Japanese rock/heavy metal singer-songwriter and vocal coach.
 Ono got his start in the 1980s as vocalist of the heavy metal band Fort Bragg.
 In 1992, he released his first solo single, "Pure ni Nare", on Sony Records.
 But it wasn't until his third single, "You're the Only...", that he hit it big.
 The single helped Ono win the "Rookie of the Year" award at the 34th Japan Record Awards and an invitation to that year's "Kōhaku Uta Gassen".
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).
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)".
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.
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 is the sixth studio album by Finnish symphonic power metal quintet Nightwish, released on September 26, 2007 in Finland, September 28 in Europe and October 2, 2007 in the United States.
 It was the first Nightwish album with the band's new lead singer, Anette Olzon, and the first album not featuring former vocalist Tarja Turunen, who was dismissed in October 2005.
 Lead songwriter Tuomas Holopainen has referred to it as the 'album that saved his life'.