Piano Sonata No. 1, Op. 28 and the Etudes-Tableaux, Op. 39 are solo piano compositions by Sergei Rachmaninov, composed in 1907-08 and 1917 respectively. Both works sit within the late-Romantic Russian piano repertoire and are characterised by dense textures, expansive lyricism and substantial technical demands, marking a developmental period in Rachmaninov's output between his earlier and later large-scale piano compositions.