Gunar Letzbor studied composition, conducting and violin at Linz, Salzburg and Cologne. His encounters with Nikolaus Harnoncourt and Reinhard Goebel ignited a deep passion for period instruments and performance practice, leading him to perform extensively with Musica Antiqua Köln, the Clemencic Consort, La Folia Salzburg, Armonico Tributo Basel and the Wiener Akademie. Gunar Letzbor founded his own ensemble, Ars Antiqua Austria, an instrumental ensemble of varying size dedicated in particular to the exploration of the rich, but neglected, baroque repertoire of his native country and its neighbours. Corollaries of this voyage of re-discovery have been not only the unexpected finds of musical masterpieces otherwise destined to languish in obscurity, but also the articulation of a uniquely central-European instrumental sound and its often deeply spiritual inspiration. As a soloist and with Ars Antiqua Austria, Letzbor has made numerous recordings (including several world premieres), featuring works by Mozart, Bach, Biber, Muffat, Aufschnaiter, Viviani, Schmelzer, Weichlein, Vejvanovsky, Vilsmayr and Conti. Particulary remarkable was his world's premiere recording of Sonate for violin solo by J.J.Vilsmayr and J.P.Westhoff.

Austrian Baroque music takes centre stage in the repertoire of this unusual Baroque ensemble. The music performed at the imperial court in Vienna at this time was initially heavily influenced by the music of Italy, later by that of France; Spanish court ceremonial also had important artistic effects in Vienna. The typical Austrian sound of this era was characterised by the impact of its many royal domains. The political and societal boundaries of Baroque Austria stretched much further than nowadays. Elements of Slavic, Hungarian and Alpine folk music styles had lasting effects on art music, making up its specific sound. But the Austrian sound also reflects the temperament and the character of the people of the time: placed within the melting pot of many diverse cultures, amalgamating Mediterranean zest for life, Slavic melancholy, French formalism, Spanish royal ceremony and the original Alpine elements of the German-speaking region. This mixture of court music and folk music with a dance-like character outlines the typically Austrian sound.
Alongside many concert performances, the early years of the ensemble Ars Antiqua Austria were dedicated to musicological research of Austrian Baroque composers. The abundance of rediscovered works led to several successful premiere recordings: albums featuring the works of R. Weichlein, H.I.F. Biber, F. Conti, G.B. Viviani, G.A.P. Mealli, G. Arnold, A. Caldara, B.A. Aufschnaiter, J.J. Vilsmayr, J.P. Vejvanovsky, J. Schmelzer, G. Muffat, W.L. Radolt, C. Mouthon, J.B. Hochreither, F.J. Aumann and J.S. Bach were met with enthusiastic approbation from the international music press.
Ars Antiqua Austria have been designing their own concert series at the Vienna Konzerthaus since 2002, and at the Brucknerhaus Linz since 2008. The ensemble is leading a cycle of performances arranged over several years entitled “Klang der Kulturen – Kultur des Klanges” (“Sound of the Cultures – Culture of Sound”), consisting of ninety concerts set to be performed in Vienna, Prague, Budapest, Bratislava, Krakow, Venice, Ljubljana, Mechelen and Lübeck.
Recent performances include concerts at the Festival de Musique Ancienne de Ribeauvillé, Berliner Tage für Alte Musik, Festival Printemps des Arts de Nantes, Mozartfest Würzburg (an opera production), Tage Alter Musik Herne, Festival de Musique de Clisson et de Loire Atlantique, Folles Journées de Nantes and Tokyo, Musée d’Unterlinden Colmar, Printemps Baroque du Sablon, Festival van Vlaanderen, Festival Bach de Lausanne, MAfestival Brugge, Bologna Festival, Vendsyssel Festival, Concerti della Normale di Pisa, Resonanzen Wien, Klangbogen Wien, Monteverdi Festival Cremona, Bayerische Staatsoper and the Salzburger Festspiele. The ensemble has also been welcomed in the USA and in Japan.
The CD recording with mezzo-soprano Bernarda Fink (four cantatas by Francesco Conti) was awarded a Diapason d’or only one week after being issued. Gunar Letzbor and his ensemble Ars Antiqua Austria were presented with the Cannes Classical Award 2002 for their recording of the Capricci Armonici by G.B. Viviani.