Concerto Gate is an MMORPG by Square Enix and Ponsbic. This is the soundtrack to an expansion pack for that game. It's new music that wasn't featured in the original CONCERTO soundtrack (http://vgmdb.net/album/7212).

VGMdb link: http://vgmdb.net/album/21456
Album title: Concerto Gate Forte Shinshou Renewal Kit ~"Rosenberg Gakuen to Nanatsu no Sekai" Hen~ SPECIAL SOUND TRACK
Composers: Hiroki Kikuta, Kenji Ito
Catalog nr: FBP003W000A20
Released: Nov 12, 2010