In 1964 she appeared in La bohème at the Vienna State Opera; she soon embarked upon an international career which took her to London, Brussels, Amsterdam, Hamburg, Hannover, Cologne, Genoa, Budapest, Paris, Barcelona, Lisbon, Chicago, New Orleans, Houston, Philadelphia, and Buenos Aires.
[2] Pilou debuted at the Metropolitan Opera on 7 October 1967 singing the role of Juliette in Roméo et Juliette;[3] during her career there she also sang Mimì in La bohème;[4] Micaëla in Carmen;[5] Zerlina in Don Giovanni;[6] Nanetta in Falstaff;[7] Marguerite in Faust;[8] Cio-Cio-San in Madama Butterfly;[9] Susanna in Le nozze di Figaro;[10] Nedda in Pagliacci;[11] Mélisande in Pelléas et Mélisande;[12] and Violetta.
[16] She also performed at the Aix-en-Provence Festival, the Internationale Maifestspiele Wiesbaden, and the Arena di Verona.
At the Opéra de Monte-Carlo, she created the lead role in La reine morte of Renzo Rossellini in 1973.
Pilou was a regular at the Greek National Opera from 1969 until 1985, performing such roles as Liú, Susanna, Cio-Cio-San, Donna Elvira in Don Giovanni, Desdemona, and Marguerite.