Chopin, Prelude Opus 28 #24
Unforgiving, is the last 3 notes. The knells of death.
Martha Argerich is the best interpreter of this piece. Note her extreme clarity.
Also, for this piece to shine, you need a bright piano. Each note is strong as steel. Feel the unforgiving twang of the steel. Mellow Steinway can go home.
Compare to Liszt Transcendental Etude #12