Most underrated composer of 20th Century?

It's a tie between Martinu and Janacek.

Great minds think alike Rpfef, Janacek was my second choice, tie-breaker was he's much better known.

I guessing probably some well known composers of music in eastern culture totally unknown in the west, much less underrated?

Duke Ellington is far from unknown, but still hugely underrated as a top echelon 20th century music composer overall IMHO.

In more traditional classical music world, how about Villa Lobos? He is high on my list of classical composers to explore deeper based on what I have heard to date.

Western classical music has always had a heavy European bias, for clear historical reasons. Are the most underrated composers of the 20th century likely to still be mined in those waters?