His activities have entailed working with important orchestras
- St. Petersburg and Hamburg Symphonies
- MDR Symphony Orchestra Leipzig
- MDR Chamber Philharmonic
- WDR Radio Orchestra Köln
- Slovak Philharmonic Orchestra
- Haydn Orchestra of Bolzano and Trento
- Latvian National Orchestra in Riga
- United European Chamber Orchestra in Milan
- Radio Symphony Orchestra of Vienna
- Tonkünstlerorchester of Lower Austria
- Vienna Volksoper
- Bruckner Orchestra Linz
- Vienna’s Burgtheater
- Ensemble Modern Frankfurt
- “die reihe“
- NDR Radiophilharmonie Hannover (in negotiation)
- Brandenburgisches Staatsorchester (in negotiation)

CD - Recordings
Ernst Theis served from 1990 to 2005 as artistic director of the Austrian Chamber Symphony, with which he put on a concert series at the Vienna Konzerthaus as well as produced a series of CDs with works from the early 20th century (on the Cantate Musicaphon label).

He and the orchestra then mounted the world’s first complete recording of all the Haydn piano concerti (2002) with pianist Massimo Palumbo (from Genoa, Italy) for the German label Arts Music.

Since the beginning of the 2003/04 season, Ernst Theis has been head conductor of the Dresden State Operetta. With his Dresden orchestra he has recorded the operettas Carneval in Rom (The Carnival in Rome) and Spitzentuch der Königin (The Queen’s Lace Handkerchief), both by Johann Strauss, for the renowned German label CPO.

Johann Strauss’ Spitzentuch der Königin was presented at the beginning of February 2009.

Carneval in Rom will follow 2010.
In August 2009 Ernst Theis has recorded the first geman-speaking Offenbachian operetta La Périchole. The presentation was broadcasted on Deutschlandradio on 20th September 2009. He will continue the recording of Offenbachian german-speaking operettas with La Grande-Duchesse de Gérolstein and Les Brigands.

For some years now, Ernst Theis has been collaborating with the broadcaster Mitteldeutsche Rundfunk (MDR). This collaboration has grown into a new, multi-year project for recordings of 20th-century works which will be presented as CD-edition by CPO. Ernst Theis has so far recorded the following works for this edition:

Franz Schreker Suite for orchestra
Ernst Toch Motley Suite for orchestra
Eduard Künnecke Dance Suite
Pavel Haas Radio Overture
Kurt Weill Berlin Requiem by Kurt Weill
Max Butting Radio Music 1
Max Butting Radio Music 2
Edmund Nick/Erich Kästner Leben in dieser Zeit (Radio play) PDF
Paul Hindemith Sabinchen (Radio play)
reconstructed orchestration by Ernst Theis

All recorded works will be presented in the form of a CD-edition by CPO. Volume I with the radio play Leben in dieser Zeit (by Nick/Kästner) was already presented in May 2010.
http://www.jpc.de/jpcng/cpo/detail/-/art/Edmund-Nick-Lyrische-Suite-Leben-in-dieser-Zeit/hnum/8575714

Actual recording plans for CPO
August 2010 – Project Radio Music
Walter Gronostay Mord (Radio play)
Wilhelm Grosz Balladen und Bänkel
Mischa Spolianspy Charleston Caprice

August 2010 – Project The unknown Johann Strauss
Johann Strauss Prince Methusalem (complete recording)