The fact that he is the only mass of the deceased in his extensive catalog, of being his last opus, unfinished (because of his death) and the mysterious circumstances surrounding his commission and composition, have built the legend and fascination that the Requiem of Mozart continues to exercise in our days.

The mystery surrounds the penultimate one of Mozart's symphonies, the Symphony No. 40; It is unknown in what circumstance, for what reason or for what character was written, and it is unknown if Mozart came to listen in life.