Vienna and its inspiring tension between tradition and modernity were the musical background in which Ernst Kovacic grew up and in which he has developed his perspective on form, sound and interpretation. Thanks to performances of J.S. Bach’s solo sonatas and Mozart’s violin concertos, as well as involvement in the field of new music, Kovacic quickly gained a high position among the violinists of his generation. Many composers (including E. Křenek, F. Cerha, G. Gruber, K. Schwertsik, and D. Bates) have composed their works specially for him. In the last concert seasons, together with Wiener Philharmoniker,
London Sinfonietta and RSO Wien, he presented the premieres of violin concertos, including by B. Furrer, D. Bates and F. Cerha, and in the 2008/2009 season, as part of the Wien Modern festival together with the Klangforum Wien he performed a new violin concerto by C. Gadenstätter.

As a soloist with the best orchestras all over the world, Kovacic has played under the baton of such conductors as: Franz Welser-Möst, Sir Roger Norrington, Sir Simon Rattle, and Esa-Pekka Salonen. He has participated in numerous prestigious music festivals around the world. As a soloist and conductor, he collaborates with many renowned chamber orchestras; in the years 1996–1998 he was artistic director of Wiener Kammerorchester. He has played with the Scottish Chamber Orchestra, the Irish Chamber Orchestra and the English
Chamber Orchestra, Royal Northern Sinfonia, Britten Sinfonia, Stuttgarter Kammerorchester, The Saint Paul Chamber Orchestra, Norwegian Chamber Orchestra, Klangforum Wien, Ensemble Modern, Camerata Salzburg, Camerata Bern and Deutsche Kammerphilharmonie Bremen. In 2008, together with Steven Dann and Anssi Karttunen, he founded the Zebra Trio. From 2007–2014 he was artistic director of the NFM Leopoldinum Orchestra.With this ensemble he performed, among others, at Festival van Vlaanderen, Brückenfestival, Warsaw Autumn 2008 and the 13th Ludwig van Beethoven

Easter Festival in Warsaw. Together with the NFM Leopoldinum Orchestra, he has recorded compositions for strings by E. Křenek and A. Berg, published by the record label Toccata Classics, and CDs with works by Beethoven, Schönberg and Janáček, as well as a selection of fugues. Ernst Kovacic plays a G.B. Guadagnini violin of 1753.