 In 1969, Kaegi was invited to compose at Utrecht's Institute of Sonology, formerly known as STEM, in The Netherlands, where he created the tape music of Hydrophonie I. Owing to a grant from the Swiss government, he permanently relocated to The Netherlands in 1971 to work at the Institute and soon became a member of the board of directors. At the Institute, Kaegi worked as a composer, researcher and teacher in the field of electronically generated music and composition – his students have among others included Benno Ammann, Lasse Thoresen, Jos Janssen, Cort Lippe, Kathleen St John, Trevor Batten, Maarten In' t Veld, Martin Supper, Peter Pabon, Kees van Prooijen. After Floris van Maanen the Canadian composer Paul Goodman, born 1955, became his assistant in the 1980s.
