Geertrudia Anna Maria van Zelm
worked at the Dutch Radio Choir in Hilversum between 1987 and 1993, as a voice teacher at the conservatory of Alkmaar (1980 and 1989) and the conservatory of Arnhem (1990 and 1995). Since 1992, Gerda has been a voice teacher at the Royal Conservatory of the Hague where from 2004- 2013 she was also the Head of the Vocal department. Gerda is a Creative Director of the Innovative Conservatoire. In 2013 she did a research project on one-to-one teaching at the Royal Conservatoire. The result of this research is published in June 2014 as a Royal Conservatoire publication.