As there was no published analysis available of this piece, I wrote my own: https://docs.google.com/document/d/e/...

The Third Sonata is written in three movements: a Prelude (0:10), a Funeral March (3:33), and an expansive third movement called “Sonata” (10:21). Marked “Misure diverse” and without a time signature, the Prelude is a brooding and improvisatory movement in G minor that introduces motivic material (the “urmotive”) in measures 1 and 2 (0:10) that defines the Sonata as a whole. This “urmotive” can be broken into two submotives that are frequently used independently: motive A, a threenote chromatic descent, and motive B, an upwards leap of a sixth followed by a descending interval. Contrasting majorkey material is introduced in 0:56, and a largescale repetition of the opening starts in 1:53. The movement finishes with a short coda in the tonic key (2:57).

The second movement, in G# minor, is entitled “Funeral March,” likely a reference to the third movement of Chopin’s Op. 35 Sonata, and also perhaps to the last movement of Scriabin’s First Sonata. The movement, which is in G# minor, opens with a transformation of the “urmotive” that opened the first movement. A second theme group, in E♭ major, is introduced in measure 9 (4:44). After a short development section, the second theme group returns (5:28), followed by the first theme in measure 37 (7:55). The first theme recapitulation (8:22) is expanded through sequence and repetition and is grounded by descending octave bass pedal points that stall on D♮ before reaching a conclusive D# in measure 48 (9:16). A plagal cadence reestablishes G# as the tonic and starts the coda in measure 49.

The third movement is the only movement written in an unambiguous sonataallegro form, including an exposition repeat (13:02), and it contains an extended development section (15:55). The movement begins and ends in G# minor, with a clear, contrasting second theme, initially presented in E major in measure 43, marked Lento (11:47). The development section consists of an introduction and a long fugue, which includes a parody of the last movement of Chopin’s B♭ Minor Sonata (   • Chopin  Piano Sonata No. 2 in Bflat...  , marked Impetuoso (18:38). Material from the introduction returns to form the retransition, with the recapitulation starting in measure 199 (19:29). The sonata concludes with a lengthy coda (20:09) that includes restatements of themes from all three movements (1st mov. at 23:07, 2nd mov. at 22:02 and 22:14, and 3rd mov. at 22:48).

Interestingly, Feinberg reuses a lot of material from the sonata in his First Piano Concerto    • Samuil Feinberg  Piano Concerto No. ...  . It is possible that this is because he didn't intend to publish the sonata.

Original recording
   • Piano Sonata No. 3, Op. 3: I. Prelude...   (first movement)
   • Piano Sonata No. 3, Op. 3: II. Marcia...   (second movement)
   • Piano Sonata No. 3, Op. 3: III. Sonat...   (third movement)


Score https://imslp.org/wiki/Special:Revers...