Greatest composer of the 20th century? Well to my ears Dmitri Dmitriyevich Shostakovich is the Greatest of All Time. Just listen to this heart-wrenching Piano Quintet in G minor, Op. 57 written in 1940:
Two years later Shostakovich scored one of the greatest public triumphs of his life with his wartime Seventh Symphony. The first three movements were written in Leningrad in the late summer of 1941 as the Nazi armies encircled the city. After the composer and his family were evacuated by air to Kuibyshev, he completed the finale. Throughout this symphony there is a genuinely powerful and profound sense of the unknown which drives the music forwards and makes its quite impossible to dismiss it as one dimensional or propaganda.
It's a one and a half hour journey that you must commit to. Early mornings or late afternoon blocks of coding are great candidates for this masterpiece to drive you through a binary war. Powerful openings, quiet melodies, and a long crescendoing march to the unknown will keep you "in the zone".