Starting in 1998 van Kreij has participated in a long running and intensive collaboration with choreographer Ted Stoffer. This resulted in music composed to a great number of dance choreographies that were performed throughout Europe and the United States. And for more than a decade he has been active within the field of music theatre trough cooperations with Dick Raaijmakers and Paul Koek.
Another important aspect of his work is the development and realisation of his own instruments. This development covers the fields of hardware—sensors and other electronics—used for gestural input, and software employing a wide range of sound synthesis models. In the role of developer, he has participated in many projects in the field of music, visual arts and architecture. Since 2001 he has been a permanent member of the teaching staff at Sonology.
Art is to the spirit what bread is to the body: a necessity without which it cannot renew itself.