Cluster is a vocal jazz group from Italy.

It was founded in 2004 by five young musicians, who were
studying at Niccolo Paganini Conservatory of Music in Genoa.
The group has spent last 3 years touring Italy and Europe
with their unique style that combines elements of jazz, pop,
and fusion. "Cement", Cluster's first album, was released in
2006 and features arrangements written by members of the group.

http://www.clustervocal.com/ita/