Gustav Mahler’s monumental Sixth is one of the darkest and at the same time most fascinating symphonies of them all. It’s dominated by a marching gesture that’s constantly modified and heightened, leading inexorably over four movements to death. Only the idyllic Andante offers some fleeting solace. In the Finale, mighty hammer blows seal the fatefulness of these annihilation-bound powers. This development is pre-empted in the first and last movements in a Janus-headed sound symbol: in the transition of the trumpets from a radiant A major into a wan, vanishing A minor via a strict rhythm in the timpani. This “Tragic” symphony leaves no one cold.