Janssens studied guitar with Frans de Groodt and at the conservatories of Liège and Brussels. He initially taught at the École Normale in Brussels. Later he became professor of orchestral conducting at the Brussels Conservatory and director of the Brussels Music Academy and Conservatory of Mons. He is the founder and president of the International Summer Festival in Brussels, where works by contemporary Belgian composers are regularly performed.
Janssens conducted orchestras u. a. in Belgium, Switzerland and Austria, the USA and Canada, Colombia and Venezuela, China and Japan, Russia Turkey, Italy and Greece. He was particularly committed to making the works of Belgian composers internationally known.
Janssens composed mainly works for large orchestra, including a piano and a cello concerto and the ballet „Yerma”, which was premiered by the Ballet de Wallonie, but also piano works and several string quartets. Among his religious works is the „Messe des artistes” and the Requiem, which was celebrated with the premiere in 2004 in Brussels with standing ovations.
He is the author of „Geschiedenis van de luit en de gitaar” (Metropolis, Antwerpen 1980).
(Rainer Stelle)