KeyMono (or Brassbastardz, as they were known then) were founded by saxophonist Alvydas Mačiulskas and trumpeter Aurimas Rimeikis in 2003. The former has played in the disco/funk collective Saulės Kliošas, but always wanted to form an acid jazz band. Trumpeter Aurimas Rimeikis participated in various theatre projects, frequently played together with DJs, and took part in experimental performances.
Having observed how moving image influences music and vice versa, Aurimas Rimeikis decided to incorporate visuals in their concerts. Thus, video artist Aleksejus Merkuljevas joined the collective. His animated music video for the track titled Jiemah won the 2005 Tango TV Awards in the nominations of the Best Debut and Most Stylish Music Video. In 2011, already changed their name to KeyMono, they won in the Electronica/Dance category of The People’s Music Awards in London.
In their music, KeyMono fuse jungle, hip hop, soul, house, big beat and drum'n'bass into something they prefer to call new groove acid jazz.
