For the few Feinberg lovers here, Sirodeau posted a video of two of the four preludes from Op. 8.
Christophe Sirodeau is the pianist who made the beautiful 2 CDs of all Feinberg sonatas, together with Nikolaos Samaltano. He also did other CDs, including the first piano concerto.
The first prelude here (No.2) is especially interesting because it clearly reminds us of Feinberg's third sonata.
The climax is almost the same of that of the sonata's second movement (the marcia funebre).
The third sonata was indeed published only after Feinberg's death, as he reused part of it for the first piano concerto.
So it's like if the sonata could be intended as a draft from which the composer drew ideas to use for other works. In reality, the sonata is maybe his most powerful work and stands very well by itself in those 3 movements which build constant tension and desperation until it explodes in the majestic third movement which is a sonata by itself (III. Sonata - Allegro appassionato); a final movement that starts with passion and speed and never slow down; it's like if in that movement Feinberg is venting all the pain that he accumulated in the previous two, trying to release all the suffering and reaching a state of bliss.
But in all movements, and also in this prelude (No.2) we have this impression that Feinberg has something inside that he needs to give vent to, and the climax is so powerful that after it the listener really feels better. Still, the dark atmosphere doesn't go away, and the piece ends calmly but with no sign of contentedness.