Harald Quaaden studied as a soloist at the Music Conservatory in Maastricht, complimenting his study as, amongst other things, a member of the opera studio Teatro dell’Opera di Roma and afterwards studied with Henk Kooijmans. Following his studies, guest appearances brought him to theatres throughout Europe. He has participated in various baroque operas such as: Sartorio’s Orpheo at the Festival Musicale del Barocco di Fano, directed by Pierluigi Pizzi, in Purcell's King Arthur at the Holland Festival and in Campra's L'Europe Galante in a tour through the Netherlands. He has worked with such renowned conductors as: Simon Preston, JanWillem de Vriend, Jos van Veldhoven and Alessandro de Marchi. He subsequently sang in a large number of operas by Mozart and Rossini. Also under the guidance of Rossini specialist Alberto Zedda (Tancredi in the Warschau Opera, in La Donna del Lago in the Avignon opera and in La Scala di Seta at the Schleswig-Holstein Festival) which lead to many more Rossini roles.
Over the past few years, he has extended his repertoire with works from names such as: Elvino (La Sonnambula), Rosillon (Die Lustige Witwe), Don Ottavio (Don Giovanni), Hoffmann (Les Contes d’ Hoffmann), Ismaele (Nabucco), Alfredo (La Traviata) en Max (Der Freischuetz). In addition, he sang under the leadership of Jeffrey Tate in Huit Scènes de Faust at the Palafenice in Venice; Adam Fischer in Il Mondo della Luna in Muziekcentrum Vredenburg Utrecht; Kenneth Montgomery in A Midsummer Night's Dream; Claudio Desderi in Il Barbiere di Siviglia in Poland; Nikolay Alexeev in Pique Dame and Jan Stulen in various concerts. He performed songs by Diepenbrock with pianist Rudolf Jansen in the radio programme de Nederlanden. In oratorio, he has an extensive repertoire, ranging from early baroque to contemporary works. One of his most frequently performed roles in this repertoire is that of Evangelist in Bach's Passions, including performances in the Amsterdam Concertgebouw and as tenor soloist in Bach's Christmas Oratorio.
Harald has worked in Music theatre with companies such as Het Huis van Bourgondië, ensemble Contraint and Struweel, with which he went on tour. He has also worked on World-premiers such as Hamelin, by the Irish composer Ian Wilson in Schleswig-Holstein and in the Netherlands in Jean Lambrechts’ suite To Remember.