Hossen has performed with outstanding musicians like Bruno Canino, Vladimir Fedoseyev, Philippe Bernold, Lior Schambadal, Leslie Howard, Adrian Oetiker, Gérard Causse, Roy Goodman, Vladimir Mendelssohn, Boris Mersson, Leon Bosch, Georges Pludermacher and Jean-Bernard Pommier - among others. Several contemporary composers have dedicated works to Hossen and Hossen has commissioned works with composers , e.g. Tomas Marco, Rainer Bischof, Walter Baer, Gheorghi Arnaoudov, François - Pierre Descamps and Alessandro Solbiati. Hossen's musicological and artistic endeavors are focused among other things on source research on Niccolo Paganini.
The complete oeuvre of Paganini for solo violin and for violin and orchestra will be released as a historical-critical edition by Doblinger Music Publisher- Vienna. Several highly acclaimed CD's with the World Première Recording of some of the most famous works by Paganini in their original version were produced by the leading italian CD Label "Dynamic" Genova. Mario Hossen plays a violin by Giovanni Battista Guadagnini, 1749, on loan from the Austrian National Bank collection and is a brand ambassador for Peugeot. Hossen plays all concerts exclusively with his preferred strings, the Vision Titanium Solo strings manufactured by Viennese company Thomastik-Infeld.