The Swedish mezzo-soprano, Ann Hallenberg, studied at the National College of Operatic Art in Stockholm with Kerstin Meyer and Erik Sædén, and graduated in 1994. She has also studied with Joy Mammen in London. Ann Hallenberg regularly appears in opera houses such as Teatro alla Scala Milan and Teatro Carlo Felice Genoa in Italy; Teatro Real Madrid in Spain; Opéra National Paris, Opéra de Lyon and Opéra du Rhin Strasbourg in France; Bayerische Staatsoper München, Staatsoper Stuttgart, Semperoper Dresden, Teatro Lirico in Bremen, Oper der Stadt Bonn, Komische Oper Berlin, and Badisches Staatstheater Karlsruhe in Germany; Opernhaus Zürich in Switzeland; Theater an der Wien, Netherlands Opera Amsterdam, Vlaamse Opera Antwerp, Opéra Garnier Monaco, Opera Montpellier, Norwegian National Opera, Royal Swedish Opera, Drottningholm Theatre Stockholm, and Volksoper in Stockholm. She has also appeared in concert halls and festivals throughout Europe and North America, such as and festivals such as Dresdener Musikfestspiele, Boston Early Music Festival, Tanglewood Festival, and Utrech Festival for Old Music. She has sung concerts in USA, Germany, Italy, France, Belgium, Holland, Sweden, Norway, Austria, England, and Switzerland.