Jazz was very appealing to Mihailo Živanović. Accomplishing himself in this field, in 1946 he formed a jazz orchestra Fis-dur which he named after his clarinet Fis-dur. The orchestra was led by Michael himself. Due to the quality, the orchestra had very soon become one of the most famous in Belgrade. The first members of the orchestra were: Milo Dimitrijević (guitar), Duško Radić (piano), Stanislav Sodermajer (drums) and Mihailo Živanović (clarinet).
Anxious to learn and progress further in music in 1946. he continued to study clarinet at the Allmusic Academy where he met Eduard Sađil, also a student of clarinet.
Orchestra Fis-dur achieved success after success: performances, tours, great delight and standing ovations of the satisfied audience. In the year 1947, there was a large change in the orchestra with the new top musicians: Predrag Ivanović (trumpet), dr Aleksandar Pejić (accordion), Milovan Vukajlović-Genije (piano and accordion), Predrag Stefanović-Grof (-Count)(trombone) and Branko Pejaković (bass). Only Sodermajer and Živanović remained of the old members.
Significant, almost crucial meeting with Boro Roković (a trumpeter, composer, arranger, pianist and accordionist) occurred while playing at a dance party in 1949. Bora heard him and was impressed by his talent. He wanted to help Mihajlo, introduce him more and better into the world of jazz and direct him to the true value. He offered him to join his orchestra. Živanović played there until the end of 1953. Soon he was invited by Aleksandar Nećak and played in all three orchestras at the same time.
Orchestra Fis-dur existed until 1950.