Equally at home with period- and modern-instrument ensembles, he has earned an outstanding reputation as a solo organist, an orchestral and opera conductor and composer. Haselböck's main focus lies in works of the Baroque and Classical periods.
As a solo organist, he has performed under the direction of conductors Abbado, Maazel, Muti, and Stein, has won numerous competitions and has made more than fifty solo recordings. Additionally, he has conducted over 60 recordings, with repertoire ranging from Baroque to 20th Century vocal and instrumental works. This prodigious output has earned him the Deutsches Schallplatten Critics' Prize as well as the Hungarian Liszt Prize.
While in his official role as Court Organist for Vienna, where he was responsible for an extensive repertoire of classical church music, Haselböck began an intense commitment to conducting, which led to his founding the now-famous Vienna Akademie Ensemble in 1985. With this period instrument orchestra, Haselböck established a year-round cycle of concerts for the Gesellschaft der Musikfreunde in the Great Hall of the Vienna Musikverein.
Haselböck frequently guest conducts major orchestras including the Vienna Symphony, St. Paul Chamber Orchestra, Deutsches Symphonie Orchester Berlin, Dresden Philharmonic, Hamburg Symphony, Flemish National Philharmonic, Radio Orchestra Hilversum, the Toronto Symphony and the National Philharmonics of Hungary, Czech Republic, Slovakia, and Slovenia. In the United States, he has conducted the Pittsburgh Symphony, Philadelphia Orchestra, San Francisco Symphony, the Detroit Symphony and the Los Angeles Philharmonic. He has also been a guest with his Vienna Akademie as Artist-In-Residence with numerous festivals including those of the Cologne Philharmonic, Suntory Hall in Tokyo, and MozartFest in Würzburg.
As an opera conductor, he made his debut with the Handel Festival in Göttingen. He regularly appears at the Zürich Opera and he conducted new productions of Mozart operas at the Theatre im Pfalzbau Ludwigshafen, using historic instruments for the first time in Germany’s modern history. In 2000-01 he created new productions of Händel's "Acis and Galatea," Gassmann's "La Contessina," and Haydn's "Die Feuersbrunst" with his Vienna Akademie, following in 2002 with productions at the Festival in Schwetzingen (Benda's "Il buon marito") and Salzburg (Händel's "Radamisto"). In 2004, he led productions of Händel's "Il trionfo del tempo" (Salzburg Festival), Mozart's "Il re pastore" (Klangbogen Wien), and Händel's "Radamisto" (touring to Spain, Istanbul, Venice, Israel, and the Concertgebouw in Amsterdam). He also conducted the U.S. premiere of Porpora's "Il Gedeone" in a concert version with Musica Angelica in Los Angeles.
When not conducting, Haselböck is busy unearthing long lost vocal/instrumental works in the dusty archives of Kiev and Vienna, finding unpublished gems by Biber, Porpora, Fux, Muffat, and the Bach family, which he transcribes and resurrects in historical re-creations for his Vienna Akademie Ensemble and festivals around the world.