The Dutch soprano, Tannie Willemstijn, studied at the conservatories of Rotterdam and Den Haag, finishing her studies in 1984. Since 1979 she has been a member of the Nederlands Kamerkoor. She has also appeared as soloist specialising in Baroque music, in concert halls and festival all over Europe, under the baton of conductors as Ton Koopman, Frans Brüggen, Sigiswald Kuijken and Philippe Herreweghe. She has sung solo cantatas with the Amsterdam Baroque Orchestra and Amsterdamse Bachsolisten.
Tannie Willemstijn has also performed works of the Romantic era and the Avant-garde, both in opera and chamber music. She made with the conductor Reinbert de Leeuw a CD-recording with works by Tristan Keuris (opera l'Infinito), Louis Andriessen (De Materie), Steve Reich (Tehillim) and Claude Vivier (Prologue). She made a name for herself with the Lieder cycle Romanzesuite by Dmitri Shostakovich with the Guarneri Trio, cycle of works by diverse composers with Reinbert de Leeuw, Anner Bylsma, Vera Beths, with the Concertgebouw Orchestra and the Radio Kamerorkest at the Kleine Zaal of the Concertgebouw.
In Berlin Tannie Willemstijn made a TV-programme with Lieder of Alban Berg and Schubert, and later sung them in recital at the theatres of Braunschweig, Berlin and Hamburg. Other TV-productions, in which she participated, included Exsultate Jubilate (Mozart), Jauchzet Gott in alle Landen (BWV 51) (J.S. Bach), Ein Deutsches Requiem (Johannes Brahms), Suor Angelica (Puccini).
With the Gelders Orkest Tannie Willemstijn sang 4th Symphony by Gustav Mahler under the baton of Guido Ajmone Marsan and the coloratura part in l'Enfant et les Sortileges under the baton of Roberto Benzi. With the Koninklijk Concertgebouworkest under the baton of Riccardo Chailly she sang at the Kerstmatinee the role of Suor Angelica by Puccini. In the USA she participated in concert performances in the roles of Amina in Sonnambula (Bellini) and Gilda in Rigoletto (Verdi) and at summer festival in concert performance in the role of Violetta in La Traviata (Verdi).
Tannie Willemstijn has performed works of the Avant-garde with the Schoenberg Ensemble, the Ives Ensemble, ASKO Ensemble and Nieuw Ensemble. Tannie Willemstijn participated in the world première of a mono-opera by Geza Frid: Het Dagboek van Anne Frank.