This is apparent in music for the stage and was later continued in works such as A Symphony in Time and the string quartets Solos and Shadows and Surrounded by Scales.
The chamber symphony Movements on a Moving Line marks the beginning of a long period dominated by an interest in time and tempo, here as a kind of time-travel where the same music seems to appear and disappear in different tempi.
Among his students: Louis Aguirre Rovira, Anne Linnet, Kaj Aune, Peter Bruun, Anders Brødsgaard, Karsten Fundal, Michael Nyvang, Jesper Koch, Niels Rønsholdt and Simon Steen-Andersen.
His books, among which several have been translated, on Glenn Gould, Robert Schumann, Sviatoslav Richter, Gustav Mahler, John Cage, Johann Sebastian Bach, George Gershwin, Pyotr Tchaikovsky, Johannes Brahms, Sergei Prokofiev and music in the 20th century have reached a wide audience.
He has further reconstructed what he believes to be Schubert's lost Gastein symphony and created an orchestral version of his melodrama Der Taucher commissioned by the Danish singer Bo Skovhus.