Now that Janacek is finally getting something resembling his due as the cosmic genius he is, there are a number of remaining candidates for Most Underrated Composer of the 20th Century. But surely Frank Martin is right near the top. He is in some ways a 1-note composer, using almost seraphic-sounding harmonies to create an ecstatic sound be his music instrumental or vocal - even during his 12-tone phase this remains true of him. But if he is a 1-noter, then so are all sorts of religious composers from Bach to Bruckner. As for the Mass for Double Choir, I would be hard-pressed to name a greater piece of 20th century music for unaccompanied chorus.