That massively depends on whom you ask. Karl-Heinz Stockhausen often is mentioned in this context - but that guy is an acquired taste, and the older I get, the

That massively depends on whom you ask. Karl-Heinz Stockhausen often is mentioned in this context - but that guy is an acquired taste, and the older I get, the more I like his work. Morton Feldman is also a household name, which I personally find compositionally uninteresting.