Kosma, a.k.a. Roskow Kretschmann is one of the six Jazzanova members. His musical foundation goes back to the year 1987 when he began to build a name for himself as a Hip Hop producer in the Berlin underground scene. With the album "Rock da Most" he had immortalized the first German Hip Hop releases on vinyl. In addition he was a collaborator at the Berlin Hip Hop label Juicefull Records. 1991 saw his departure from the label job as well as from the production of Hip Hop tracks.

Kosma has been a Jazzanova member since the beginning in 1995, when Jazzanova was founded as a DJ team, transforming into poduction in 1996, the same year Kosma released his first solo album "Universal?.

With the opening of the borders to Eastern Europe his interest in the Eastern European jazz scene increased, which clearly had an influence on his work. An additional influence by that time came from his love for the American label CTI and Bob James, to whom he dedicated "Atlantis" from his debut album "Universal".

Besides his work for Jazzanova he released a new Kosma tune in 1997 entitled "Mikrokosmos" on the INFRACom! label compilation "Fast Forward" a 9:50 minute epic sound track in 3/4 time which brought him additional respect, as well as a 12" entitled "Kalderon/Sinther" in February 1999. For a short time Roskow Kretschmann used to produce by the name of Sygaire for Sonarkollektiv.

Kosma completed a series of 12" in March 2005, shortly before the release of his second album "New Aspects".

By the name of Roskow he is a resident at "Plattenk?che? in Berlin?s "Klub der Republik.?