Sidsel Aja Eriksen grew up in Als in Southern Jutland and studied in Aarhus with Ingrid Haking Raaby and Bodil Øland and in Amsterdam with Rosemary Joshua. She made her debut at the Jutland Conservatory of Music in 2018.
Sidsel debuted in 2021 at the Royal Opera in the role of the Flower Boy in Nielsen's Maskarade and the following year she sang a cover of Bevidstheden in Alenius' Manualen from the stage. She has sung several children's operas around Denmark with Operaen i Midten, the Tour with the Operetta Kompagniet and at Den Fynske Opera she has sung Tisbe in Rossini's Cenerentola and the role of Her in Græsset er Grønnere by Oh Land and Adi Zukanovic.
In addition, she has sung several times at Aarhus Summer Opera, including in the premiere of John Frandsen's Year of the Beast 1666 in the role of Anne-Marie. At the Copenhagen Opera Festival, Sidsel was part of the production of Puccini's Suor Angelica in the role of Maestra delle novitie and with Opera Hedeland and Operaen i Midten she sang the role of Papagena in their streaming recording of Mozart's Magic Flute.
On the international stage, Sidsel made her debut at Läckö Castle in Sweden in the lead role of Tintomara in Werle's opera of the same name and in Germany she appeared on stage at the Immling Festival as the title role in Rossini's Cenerentola.
Sidsel has worked as a soloist with several large orchestras, including Aalborg Symphony Orchestra and Aarhus Symphony Orchestra, Randers Chamber Orchestra, Helsingborg Symphony Orchestra and DR's Symphony Orchestra. With these, she has, among others, sung Moderen in Gade's Elverskud, Alto soloist in Bach's B-minor Messe and Christmas Oratorio and Handel's Messiah, Rosina in a concert performance of excerpts from Rossini's The Barber of Seville and the role of the 2nd Tern in the CD recording of Hornemann's Aladdin.
