In 2013 he warmed up for Jamiroquai as frontman of the funk/hip hop band FreeStyle. Together they released the band's album 'No Time to Play' in 2012. The song 'Na Dve' (In Two) is the debut of Rosen as a solo artist, though most of the radiostations in Bulgaria acknowlidge his presense in the musical air and introduce the song as a follow-up of K-Ross' carreer. The song 'Na Dve' is a co production between Rosen and FREAK Collective-a crew of young and very talanted musicians/composers/producers,co-signed by some of Bulgaria's top selling artist like BoBo, Ruth Koleva, Lora Karadjova,as well as international stars like Mark Morrison, Blackstreet, Truth hurts.Thanks to the director Victor Ivanov, who has worked with Guilermo del Toro on a multi-million dollar production, the song 'Na Dve' is backed up by a stylish video. In the autumn of 2015 K-Ross was honored in a competition organized by the Bulgarian National Radio called “Zlatna Prolet”, with Participation in the Eurosonic festival in Groeningen and Second prize as well. You can watch the video of "Na Dve" in the following link.http://www.youtube.com/watch?v=KkHW66hUwBY.