Born in Austria in 1976, Günther Groissböck studied in Vienna with legendary singers such as José Van Dam and Robert Holl. After starting his career as a company member of the Vienna and Zurich operas, he began performing internationally, establishing his reputation as a renowned bass throughout Europe and North America.

He has appeared with leading orchestras and eminent conductors at prestigious venues all over the world, including the Wiener Staatsoper, the Teatro alla Scala, the Opéra National de Paris, the Royal Opera House Covent Garden, the Metropolitan Opera, New York, the Bayerische Staatsoper, Munich and the Salzburg and Bayreuth festivals.

A consummate performer, he has collaborated with Sir Antonio Pappano, Philippe Jordan, Yannick Nézet-Séguin, Kirill Petrenko, Valery Gergiev, Sir John Eliot Gardiner, Donald Runnicles, Marek Janowski and Zubin Mehta, among others.

The tenor Karl-Michael Ebner was born in Schärding am Inn in Austria. A soloist with the Vienna Boys' Choir, he subsequently studied the oboe, conducting and singing at the Academy for Music and Performing Arts in Vienna. From 1990 to 1996 he studied singing at the Bruckner University in Linz, and was then a student of Km. Gerdrude Grob-Brandl. He has been Artistic Director of the Steyr Music Festival since 1995 and General Director of the Bad Hall Kurtheater for Opera and Musicals since 1997, as well as Leader of the USO vocal ensemble since 1990. He is active as a concert soloist in church music and opera and stage performance. In 1996 he made his début at the Linz State Theatre in Cavalieri's La rappresentazione di anima e di corpo at the International Bruckner Festival. He has performed as a soloist in numerous radio and commercial recordings with the USO vocal ensemble, the Vienna Symphony Orchestra and many others. Since the 1999/2000 season, he has been an ensemble member of the Vienna Volksoper, and in 2001 made his début at the Vienna State Opera as Monostatos in Die Zauberflöte. Guest contracts have taken him to the United States, Hong Kong, Beijing, and Macao, and to the Bruckner Festival. Karl-Michael Ebner's unusually large repertoire includes more than thirty rôles, ranging from Don Basilio in Le nozze di Figaro and the Steuermann in Die fliegender Holländer to Freddy in My Fair Lady and Jean-Michel in La cage aux folles.