With an internationally recognized career spanning more than two decades, tenor Thomas Cooley continues to set the standard in his field, delighting audiences with unforgettable performances in North and South America, Europe and Asia. His engagements have taken him to 30 US states and numerous countries around the world.

Cooley has performed in renowned concert halls such as Carnegie Hall, Concertgebouw, Konzerthaus Berlin, Berlin Philharmonie, Tonhalle Zurich, Symphony Hall Boston, Avery Fisher Hall, Konzerthaus Vienna, Walt Disney Hall, Kennedy Center, Bavarian State Opera, Tchaikovsky Hall in Moscow, KKZ Lucerne, Festival Hall Osaka and Esplanade Hall in Singapore. He has worked with renowned conductors such as Helmuth Rilling, Donald Runnicles, Teodor Currentzis, Michael Tilson Thomas, Nicholas McGegan, Robert Spano, Franz Welser-Möst, Bernard Labadie, Harry Bicket and Wolfgang Sawallisch, Osmo Vänskä, Eiji Oue, Lan Shui, Matthew Halls, David Robertson, Dame Jane Glover, Markus Stenz, Carlo Rizzi, Thomas Søndergård, Manfred Honeck, Jaap van Zweden, Edo de Waart, Paul McCreesh and Andrea Marcon.

His most important engagements include regular appearances with internationally renowned orchestras and ensembles such as the Bavarian Radio Symphony Orchestra, the Gewandhaus Orchestra Leipzig, the New York Philharmonic, the Minnesota Orchestra, the St. Paul Chamber Orchestra, the Copenhagen Philharmonic, the National Symphony Orchestra, the Atlanta Symphony Orchestra, the Orchestre Symphonique de Québec, the St. Louis Symphony Orchestra, the National Arts Centre Orchestra Ottawa, the Orchestra of St. Luke's, Trinity Wall Street, St. Thomas Fifth Avenue, the Singapore Symphony Orchestra, the Mark Morris Dance Group, the Jerusalem Symphony Orchestra and the Osaka Philharmonic.

A proven specialist in the works of Handel and J.S. Bach - particularly in the role of the Evangelist - Cooley has performed with renowned ensembles such as the Thomanerchor and the Gewandhausorchester Leipzig, the Windsbacher Knabenchor and the Akademie für Alte Musik Berlin, the Dresdner Kreuzchor and the Internationale Bachakademie Stuttgart. He works regularly with historically informed ensembles such as the Philharmonia Baroque Orchestra, the Handel Festivals in Göttingen and Halle, Les Violons du Roy, MusicAeterna, Tafelmusik, the Handel and Haydn Society, Boston Baroque, the Bach Festivals in Carmel and Oregon, Pacific MusicWorks, Music of the Baroque and the Munich Bach Choir.

Cooley works closely with baroque specialist Nicholas McGegan, with whom he has performed over one hundred concerts at the Göttingen Handel Festival, with the Philharmonia Baroque Orchestra, the Cantata Collective and with leading orchestras throughout the United States. He has also made numerous CD recordings.

From 2002 to 2006, Thomas Cooley was a member of the ensemble at the Staatstheater am Gärtnerplatz in Munich. In the course of his career, he has performed over 35 operatic roles at major opera houses such as the Bavarian State Opera, the Krakow Opera, the Minnesota Opera, the Cincinnati Opera, the Göttingen Handel Festival and with the Mark Morris Dance Group at Lincoln Center.

His discography includes over 20 recordings on labels such as Carus, CPO, Deutsche Grammophon, Hänssler, MDG, Orchid Classics and Sony. A new recording of Bach's St. Matthew Passion under the direction of Nicholas McGegan will be released by Avie Records in 2026.

In 2025, Thomas Cooley was appointed Visiting Associate Professor of Voice at the Jacobs School of Music at Indiana University. He was previously on the faculty of Choate Rosemary Hall.

Hein Mulders has been Artistic Director of Oper Köln since the 2022/23 season. After successfully completing his studies in art history, musicology and opera history in Amsterdam, among others, he began working in the vocal department of a leading music agency in The Hague as assistant to the management. He then took on the position of orchestra director of the Dutch National Youth Orchestra. In 1995 Hein Mulders joined the Vlaamse Opera in Antwerp/Ghent as casting officer and one year later became part of the management team as head of casting and artistic planning. In the summer of 2006, he moved to the Nederlandse Opera in Amsterdam as Opera Director. From 2013 to 2022, he was Artistic Director of the Aalto-Musiktheater Essen, the Philharmonie Essen and the Essen Philharmonic Orchestra, when these three divisions of Theater und Philharmonie Essen (TUP) came under one management for the first time. Hein Mulders is a jury member of numerous international singing competitions.

Christopher Ward, born in London in 1980, has been General Music Director at Theater Aachen since 2018. Prior to this, he was First Kapellmeister at the Saarländisches Staatstheater in Saarbrücken from 2014 to 2018. From 2009 to 2013, he was Kapellmeister and assistant to the General Music Director at the Bavarian State Opera. Prior to this, he worked as Kapellmeister and solo repetiteur at the Staatstheater Kassel from 2005 to 2009. His first permanent position took him to the International Opera Studio of the Zurich Opera House in 2004/2005 as conductor and répétiteur. Prior to this, in 2003/2004, he was a scholarship holder in the area of accompaniment at Scottish Opera and at the Royal Scottish Academy of Music and Drama in Glasgow.

Ward began his musical career as a choirboy at Magdalen College in Oxford (1989-1993). He was then a pupil and scholarship holder at Tonbridge School in Kent, where he later also served as head boy. From 1998 to 2002 he studied music at Merton College, University of Oxford, where he was an organ scholar. During his studies he conducted various ensembles, including The Arcadian Singers of Oxford University (1999-2000) and the Oxford University Philharmonia and Chorus (2000-2001). From 2001 to 2003 he was organist at St. John's College, Oxford. He then completed a postgraduate course in accompaniment at the Guildhall School of Music and Drama in London.

Christopher Ward holds a Bachelor's degree (B.A. Hons) in Music and a Master's degree (M.St.) in Musicology from the University of Oxford, which he completed with distinction. He also holds a Postgraduate Diploma in Coaching from the Guildhall School. He has extensive instrumental training with ABRSM Grade 8 (with distinction) in piano, organ, violin and voice. His school qualifications include 10 A* grades and one A grade at GCSE, as well as A levels in Physics, Mathematics and Music (all A) and English (B).

"Enchantingly pure" (Opernwelt), "...with sheer endless breath..." (Das Opernglas), "...a high degree of physicality..." (Opernglas) and "...with erotic impetus..." (Norddeutscher Rundfunk): Kai Wessel's singing is described with such attributes and ennobled with "...was one of the most lyrical, natural-sounding, evenly-registered counter-tenors I have ever heard" in the English magazine Opera.

Born in Hamburg, Kai Wessel initially studied music theory (Prof. Roland Ploeger) and composition (Prof. Dr. Friedhelm Döhl) at the Lübeck University of Music, and later also studied singing with Prof. Ute von Garczynski, who discovered and trained his alto voice (concert exam with distinction). At the same time, he studied baroque performance practice at the Schola Cantorum Basiliensis with René Jacobs, whose assistant he was for arrangements of several operas.
He won prizes at the VdMK competition in Berlin (including a special prize from the German Stage Association for the best interpretation of a contemporary work) and the Concours Musica Antiqua at the Flanders Festival in Bruges and received scholarships from the Studienstiftung des Deutschen Volkes and the DAAD (further training with Peter Kooy, Holland).

Kai Wessel is one of the leading representatives of his field, invited by orchestras and conductors all over the world (including Philippe Herreweghe, Nikolaus Harnoncourt, Gustav Leonhard, Jordi Savall, Ton Koopman, William Christie, Nicholas McGegan, Reinhard Goebel, Mazaaki Suzuki, Martin Haselböck, Michael Schneider, Hermann Max, Michel Corboz, Hans-Werner Henze, Ivan Fischer, Markus Stenz, Kent Nagano, Franz Welser-Möst, Sylvain Cambreling, Arturo Tamayo, Heinz Holliger, Peter Rundel), documented by radio, television and over 100 CD recordings.
Guest appearances have taken him to opera houses in Barcelona, Nice, Hamburg (premiere of B. Friedrich's "Lancelot's Mirror"), Hanover, Berlin (Deutsche Oper, premiere of Isabel Mundry's "Ein Atemzug - Odyssee"), Munich (premiere of Jörg Widmann's "Babylon"), Dresden, Cologne, Stuttgart, Freiburg, St. Gallen and the Theater Basel, where he was a guest artist from 1994 to 2004. There he appeared under the direction of Herbert Wernicke ("Theodora", "Aus Deutschland", "Giulio Cesare", "Wie liegt die Stadt so wüste", "Actus tragicus", "Israel in Egypt"), Joachim Schlömer (as Orfeo in Chr. W. Gluck's "Orfeo ed Euridice" and as Andy in the world premiere of Olga Neuwirth's "Lost Highway"), Karin
Beier and Claus Guth (as the Armenian Boy in the world premiere of Klaus Huber's "Schwarzerde").
He has also appeared in stage productions at festivals for baroque or contemporary music, such as the Handel Festivals in Göttingen (Joacim, Unulfo, Arsace, Giulio Cesare), Halle (Unulfo, Bertarido) and Karlsruhe (Giustino, Cleofe), in Schwetzingen (world premiere of S.Sciarrino "Luci mie traditrici", UA G.F.Haas "Thomas"), Vienna and Salzburg (S.Sciarrino "Luca min traditrici", A.Reimann "Lear"), Amsterdam and Venice (M. Kagel "Aus Deutschland"), Innsbruck, Bregenz (UA G.F. Haas "Die schöne Wunde") and Zurich (UA R. Irman "Poem ohne Held").

Works have been written for his voice by Annette Schlünz, Rebecca Saunders, Karola Obermüller, Chaya Czernowin, Mauricio Kagel, Heinz Holliger, Klaus Huber, Matthias Pintscher, Stefano Gervasoni, Helmut Oehring, Dániel Péter Biró and others.
Kai Wessel is Professor of Singing and Historical Performance Practice for Singers at the
Hochschule für Musik und Tanz Köln. As part of this activity and as a teacher of singing at the Konservatorium Wien Privatuniversität (2006-2012), he conducted revivals of Francesco Pistocchi's pastorale "Il Narciso" (WDR 2008/11), Antonio Caldara's oratorio "Il Batista" (WDR 2015) and a revival of the pastorale "La Ninfa contenta" by Giacomo Greber (WDR 2021) under his direction (studies with Jerome Preysinger).
From September 2014 to January 2020, Kai Wessel was also a lecturer in singing with a focus on contemporary vocal literature at the Bern University of the Arts and, in the 2019/20 academic year, interim lecturer in singing at the Haute École de Musique Genève.
Kai Wessel is the editor of numerous Baroque vocal works (J.W. Franck, F.A.M. Pistocchi, J.Ph. Sack, G.Ph. Telemann and others) for Edition Walhall and co-editor of the Schott Campus volume "Der Countertenor".

Soprano Mirella Hagen began her career as a member of the opera studio at the Stuttgart State Opera, where she worked with conductors such as Manfred Honeck and Marc Soustrot. There she sang roles such as Ännchen (Der Freischütz), Anna Kennedy (Maria Stuarda) and the Flower Girl (Parsifal).

After gaining further experience as an ensemble member at Theater Regensburg, Opera Vlaanderen, Oper Dortmund and Staatstheater Braunschweig, she began her freelance career with a large repertoire.

Mirella Hagen sang at the Theater an der Wien (Helena, Morgana, Waldvogel, Woglinde), at the Semperoper Dresden (Pamina, Gretel), at the Staatsoper Stuttgart (Pamina), at the Grand Théâtre Genève and the Bayerische Staatsoper (Waldvogel), Opéra National de Lyon (Ciboletta), Landestheater Detmold (Susanna), Komische Oper Berlin (Širin), Oper Graz (Hanne - Jahreszeiten). Under Kirill Petrenko she sang Woglinde and Waldvogel in Frank Castorf's Ring cycle at the Bayreuth Festival. She made her debut at the Elbphilharmonie shortly after the opening with Rheingold (Woglinde) under Marek Janowski and the NDR Symphony Orchestra. With Sir Simon Rattle she interpreted Woglinde in Rheingold with the BR Symphony Orchestra. The performance was released on BR Klassik.

She worked closely with Helmuth Rilling, with whom she sang various Bach cantatas and "Exsultate, jubilate" in Seoul (Korea) and Milan (Italy), as well as Mozart's Mass in C minor. She has appeared with René Jacobs in pieces such as Falstaff (Salieri), Il ritorno d'Ulisse in Patria (Monteverdi), Le nozze di Figaro (Mozart) and Orpheus (Telemann).
She has worked with orchestras such as the Budapest Festival Orchestra, the SWR Symphony Orchestra, the Bavarian Radio Symphony Orchestra, the Freiburg Baroque Orchestra, the Akademie für Alte Musik Berlin, the Internationale Bachakademie Stuttgart, Concentus Musicus Wien and Belgium's B'Rock, as well as Collegium 1704.

Mirella Hagen has sung on the most famous concert stages such as Concertgebouw Amsterdam, Wiener Konzerthaus, Elbphilharmonie Hamburg, Gasteig Munich, Kölner Philharmonie, Baden-Baden Festspielhaus, Liceu Barcelona, Bozar Brussels, Konzerthaus Berlin, Tonhalle Zurich Seoul Arts Center, Tonhalle Zurich, Teatro Olimpico and others. She works with the best conductors of today such as Iván Fischer, Kirill Petrenko, Sir Simon Rattle, René Jacobs and Antonello Manacorda.

During the pandemic, she was invited by Deutschlandradio Kultur to sing live concerts for radio audiences and recorded numerous works, including Hugo Wolf's Italian Songbook. Since studying with Prof. Ulrike Sonntag in Stuttgart, she has sung many recitals, for example at the Villa Wahnfried Bayreuth and the International Hugo Wolf Academy in Stuttgart.

Yoshiko Hashimoto was born in Hiroshima, Japan, in 1977 and began her piano studies with Prof. Mari Takeda at the Tokyo College of Music in 1996. This was soon followed by a prize at the JPTA piano competition in Tokyo. As part of her piano diploma in 2000, she received a distinction in piano duet. Since October 2002 she has been living in Cologne, where she studies with Prof. Jürgen Glauss in the class for song accompaniment at the Cologne University of Music and received a prize for accompaniment at the 2005 Cologne Song Competition, and has performed in numerous concerts as a song accompanist in Europe and Asia.Since 2003 she has accompanied in the singing classes of Prof. Henner Leyhe, Prof. Klesie Kelly-Moog, Prof. Edda Moser, Prof. Arthur Janzen, Prof. Phillip Langshaw and their vocal master classes, and since 2006 she has held a teaching position as accompanist for the scenic lessons, the opera projects and several singing classes at the Cologne University of Music. As a répétiteur she worked with the WDR Rundfunkchor on several projects and concerts and was a substitute at the Theater Bonn. In 2006 she won the scholarship of the Richard Wagner Foundation Cologne.