Prelude in A-flat major (Rachmaninoff)

The work is three-part ternary; however, it assumes monothematic characteristics. The first occurrence Section A comprises measures 1–19, Section B of 19–43, Section A returns from measures 43–70, and the coda is placed at measures 70–78.

A right hand figuration extends over a descending quarter-note melody in the first two bars, outlining the A flat chord. This motive repeats, and then is varied in measures 5–8, in succession. From measures 9–18, the section is restated though a transient modulation to E major (at measure 15). An imperfect cadence in the tonic bridges the transitory gap in measure 18 to the B section in E flat.

Measures 19–20 introduce a variant of the main motive. Now in a new key, the bass melody changes, descending chromatically in an eighth-note figure.

Measure 19

A transition section comes together though the combination of ascending and descending chromatic scale fragments at measures 31–41. Measures 30 and 31 contain a subtle but clear motive (in the left hand) that reappears again (in a slightly different manner) in the 2nd Symphony (1st movement). Vertiginous modulations swing through E flat – G – C – F – A flat and B flat, before settling into E flat at measures 39–41.

Measures 32 and 33

The original statement occurs beginning at measure 42, and then a progression at measures 54–62 through F- B flat – D flat and F minor provides a link to measures 61–70, where the harmonies become vague and undistinguishable:

Measures 61 and 62

The coda exhibits a gradual breakdown of the forward motion, and, with a quarter-note progression in the final three bars, the A flat tonality is reestablished.

Measures 76–78