He studied at the Hochschule für Musik und Tanz Köln, where his teachers included Günter Bialas and Hans Werner Henze (composition), Siegfried Palm and Erling Blöndal Bengtsson (cello) and the Amadeus Quartet (chamber music).
As a composer and chamber musician, he occupied various teaching posts, including a lectureship in composition at the University of Mainz (1984–85) and a guest professorship at the National Conservatory of Hanoi (1997–99).
Thus, there are instrumental works and cycles based on pictures by Marc Chagall, Paul Klee, Wassily Kandinsky, Albrecht Dürer and especially Francisco Goya (El sueño de la razon produce monstruos, 1982; Desastres de la guerra, 1983; Los disparates, 1988).
The literary figures who have most left their mark on his music are Ranier Maria Rilke, Paul Celan, Samuel Beckett and Stéphane Mallarmé.
Denhoff's compositional vocabulary shows evidence of a sensitive feeling for harmony and form, whose roots are to be found in composers such as Bernd Alois Zimmermann, Olivier Messiaen, Morton Feldman and György Kurtág.