There are at least 2 bands named "Adagio":

1) Adagio is a French neo-classical progressive band hailing from Montpellier, France, formed in 2000. Stephan Forté, the band's guitarist, is considered the creative force behind Adagio. Adagio's music is characterized by technical precision, dark, dense orchestration, complex lead work, and a driving rhythm section. On the group's 2006 release Dominate, they added death grunts to their sound. The band has finished the pre-production of their 4th album, Archangels in Black, which is scheduled for release in February 2009.

Adagio's official website: http://www.adagio-online.com
Adagio's MySpace: http://www.myspace.com/adagioofficial
Adagio at Wikipedia: http://en.wikipedia.org/wiki/Adagio_(band)
Adagio at the Encylopedia Metallum: http://www.metal-archives.com/band.php?id=754

2) Adagio is a doom/death metal band from Brazil.

Adagio's MySpace: http://www.myspace.com/adagiodoommetal
Adagio at the Encylopedia Metallum: http://www.metal-archives.com/band.php?id=11294

3) Adagio is a hungarian crossover band.
Web: http://www.adagio.hu