starrynight

But in what form? The use of dissonance in music could go back to Jean-Fery Rebel's The Elements, Haydn's Creation, Mozart's Dissonance Quartet. Ives uses it apparently as a contrast to tonal elements in some of his pieces as well. Prokofiev may have done some early dissonant piano pieces.

One area Ives may have been original - if it really matters - is polytonality. Not sure many composers since have really used that technique (again, if it really matters whether it's influential or not).

I think the crucial knowledge for people listening to experimental music is really just getting used to a style a piece of music is in That could be classical, jazz, electronica or other kinds of music