World Tour of the Century was a concert tour by Nightwish in 2002 and 2003 to promote their fourth album, "Century Child", released on June 24, 2002.
 The tour was the debut of Marco Hietala, that replaced Sami Vänskä as bassist in 2001.
 A subsequent tour DVD was released, "End of Innocence", with a limited release of a live CD made during a concert at Summer Breeze Open Air Festival, in Germany.
Lazarus were a 1970s American soft rock band.
 The members of Lazarus were Billie Hughes, Gary Dye, and Carl Kessee.
 Bill Hughes was the leader of the band, lead singer, songwriter, and played guitar and violin.
 The band "Lazarus" were early artists in the Contemporary Christian movement.
"Hummingbird" is a song by American soft rock duo Seals and Crofts, released as a single in 1973.
 It was the second single from their fourth studio album, "Summer Breeze", the follow-up to the LP's title track.
Callenish Circle was an extreme metal band from the Netherlands.
 They recorded three of their albums for Metal Blade Records, and broke up in February 2007.
 In the early 2000s things were going well for the band.
 In 2002 they toured with God Dethroned, played at the Dutch version of Ozzfest and the German Party San Open Air, and opened for Dimmu Borgir.
 Their fourth album was released by Metal Blade in 2003; to support it they played that year's Wacken Open Air and Summer Breeze festivals in Germany, and in October they were part of the Bonded By Metal Over Europe-tour, headlined by Exodus, Nuclear Assault, and Agent Steel.
 In 2006 they toured Mexico (cited by the band as the high point of their career), before they decided to break up in 2007.
Nothing to Lose is the fourth studio album of the Danish soft rock band Michael Learns to Rock.
 It was released on September 12, 1997 by Medley Records in Denmark.
 Like the previous album, "Played on Pepper" (1995), it was mainly produced by the band itself.
 Guitar player Mikkel Lentz said the band programmed new beats during the mixing process as they wanted to experiment a bit more with this album.
 While the band's previous albums relied heavily on soft rock ballads, "Nothing to Lose" also contains a rockier sound intended to suit the European market.
 Bass guitar player Søren Madsen debuts as songwriter on the track "Magic".
Summer Breeze is the fourth album by the American soft rock band Seals and Crofts, released in 1972 through Warner Bros.
 Records.
 It was a major commercial breakthrough for the group, and peaked at #7 on the Billboard album chart.
 The title cut was released as a single on September 9, 1972, peaking at #4 on the Adult Contemporary chart, and #6 Pop.
 "Hummingbird" was the second single, climbing to #12 AC, #20 Pop, and #40 on the Canadian RPM Magazine charts.
"Diamond Girl" is a song by American soft rock duo Seals and Crofts, released as a single in 1973.
 It is the title track of their fifth studio album, "Diamond Girl".
 Like their previous top 10 hit "Summer Breeze", "Diamond Girl" also reached No. 6 on the "Billboard" Hot 100, and No. 4 on the Adult Contemporary chart.
The Sound of Bread, Their 20 Finest Songs is a compilation album by American soft rock band, Bread, released in November 1977 by Elektra Records in the UK.
 It reached Number 1 on the UK Album Chart.
 The album was issued in the US in 1985 as Anthology of Bread.
Seals and Crofts were an American soft rock duo made up of James "Jim" Seals (born October 17, 1941) and Darrell "Dash" Crofts (born August 14, 1938).
 They are best known for their Hot 100 No. 6 hits "Summer Breeze" (1972), "Diamond Girl" (1973), and "Get Closer" (1976).
Super Hits is a compilation album by American soft rock band Toto.
 It was released in 2001.
 The album has been repackaged under different several times, as "Rosanna" in 2004, as "Collections" in 2006 and as "Toto" in 2009.

Question: Summer Breeze is the fourth album by which American soft rock band?
Answer: Seals and Crofts