He completed his studies at the Belgrade Academy of Music, under the tuition of professor Bruno Brun, and pursued them at the Conservatoire superiéur de musique in Paris, with professor Ulysse Delécluse.
Performance and teaching activities
Ačkun gave concerts as a soloist in nearly all great towns in Yugoslavia, as well as in France, West Germany, Austria, Italy and Bulgaria, playing under the leadership of such conductors as Zubin Mehta, Jean Martinon, Charles Bruck, Krešimir Baranović, Oskar Danon, Milan Horvat, Živojin Zdravković.
Awards and honors
He won several important prizes, including the First Prize at the Competition of Yugoslav Performing Artists in Skopje and was a prize winner in the ARD International Music Competition (both 1954). He was also rewarded the UMUS award for the best music performance achievement in the previous concert season (1984).
He was a jury member on various competitions, including the 1987 Jeunesses Musicales International Competition in Belgrade, along with James Campbell (Canada), Walter Boeykens (Belgium), John McCaw (UK), Ludwig Kurkiewicz (Poland), Vyacheslav Ovchinnikov (U.S.S.R.), Milenko Stefanovic (Yugoslavia), Marko Rudzak (Yugoslavia) and Stjepan Rabuzin (Yugoslavia).
In 1992 he was a jury member on the ARD International Music Competition in Munich, along with Eugene Rousseau (United States), Eduard Brunner (Switzerland), Philippe Cuper (France), Giora Feidman (Argentina), Lutz Kŏhler (Germany), Lew Mikhailow (U.S.S.R.), Charles Neidich (U.S.A.) and Ulf Rodenhäuser (Germany).
Ačkun was a member and president of the Association of Musical Artists of Serbia.
- Barker, John Craig: The Jeunesses Musicales Belgrade International Competition, The Clarinet, February/March 1988
- Dizon, Kristine. "Croatian Clarinet Concertos." Clarinet & Saxophone, Vol. 43, No. 1 (Spring 2018), pp. 22-25.
- Eberst, A.  : Klarinet i klarinetisti, Forum, Novi Sad
- Gillespie, James: The International Clarinet Competition of the ARD-Munich, The Clarinet, September 2003
- Lawson, C. J. (1995), The Cambridge Companion to the Clarinet, Cambridge University Press
- LP 2130556 STEREO, Produkcija gramofonskih ploča Radio-televizije Beograd, Beograd
- Maksimović, M. (1971): Beogradska filharmonija 1951-1971, Beogradska filharmonija, Beograd
- Muzička enciklopedija, I (1971), Jugoslovenski leksikografski zavod, Zagreb
- Muzika i muzičari u NOB - Zbornik sećanja (1982), Grupa izdavača, Beograd
- Pedeset godina Fakulteta muzičke umetnosti (Muzičke akademije) 1937-1987 (1988), Univerzitet umetnosti u Beogradu, Beograd
- Pejović, R. (1986): Oskar Danon, Univerzitet umetnosti u Beogradu, Beograd
- Peričić, V. : Muzički stvaraoci u Srbiji, Prosveta, Beograd
- Svet Plus[permanent dead link], 28 September 2009
- Vremeplov RTS-a, 28 September 2009
- Walzel, Robert: The Belgrade Competition - A First Hand Account, The Clarinet, February/March 1988