Luderart, seconded. I have long felt that Beethoven is one of the most modern-sounding composers, although this may be because he is still influential today and so does not seem outdated. Actually this brings up a different avenue of enquiry to this subject: should we assume that all contemporary music is actually 'modern'? Aside from composers who intentionally set out to write in a 'historicist' style, such as our own J. Lee Graham, or the school of medieval revivalists, if a work has a surface style that is novel but uses the underlying structure of music from a past era (or vice versa) can we really declare it modern? Or is all music bound to have some past influence and the degree of modernity is determined by other factors such as aesthetics?