Prelude in F-sharp minor (Rachmaninoff)

1 is a composition by Sergei Rachmaninoff completed and premiered in 1903.

The "A" section (measures 1–13) introduces the first theme, section "B" (13–30) introduces a new set of variations, and measures 30–41 mark an altered return to the original "A" theme.

Each of the larger ternary sections contains its set of "micro-variations" marked by changes in note values, dynamics, and rhythm.

A "hidden" chromatic sequence in the "A" section occurs in the bass line on the second beat of measure 1 and the first beat of measures 2–6.

This sequence is later revealed as the basis for the "B" theme, first introduced transitorily as a modulation between the "A" and "B" sections.