The composer Sergei Rachmaninoff produced a number of solo piano pieces that were either lost, unpublished, or not assigned an opus number. While often disregarded in the concert repertoire, they are nevertheless part of his oeuvre. Sixteen of these pieces are extant; all others are lost. Ten of these pieces were composed before he completed his Piano Concerto No. 1, his first opus, and the rest interspersed throughout his later life. In these casual works, he draws upon the influence of other composers, including Frédéric Chopin and Pyotr Tchaikovsky. The more substantial works, the Three Nocturnes and Four Pieces, are sets of well-thought out pieces that are his first attempts at cohesive structure among multiple pieces. Oriental Sketch and Prelude in D minor, two pieces he composed very late in his life, are short works that exemplify his style as a mature composer. Whether completed as a child or adult, these pieces cover a wide spectrum of forms while maintaining his characteristic Russian style. Works In the autumn of 1885, the twelve-year-old Rachmaninoff entered the home of Nikolai Zverev to receive private piano instruction and at the end of May 1886, Zverev took his students to Crimea, where Rachmaninoff continued his studies, hoping to gain entrance to Anton Arensky's harmony class at the Moscow Conservatory. It was during this time that Rachmaninoff created his first composition, a two-page Étude in F-sharp major (the manuscript is now lost). After admission to the class, he produced more exercises, the earliest of which is a Lento in D minor; it is the only surviving piece of ten he is said to have composed. Now beginning to compose independently, Rachmaninoff's next project was a group he titled Three Nocturnes, and is regarded as his first serious attempt at writing for the piano. The first nocturne, in F-sharp minor, was written 14–21 November 1887, and has three parts: a beginning and an end in andante cantabile and a central section in allegro. The slower andantes are gentle sections, influenced by Pyotr Tchaikovsky, while the allegro is unnatural and stiff and unusually fast for a nocturne. The second piece, in F major, followed on 22–25 November, also contains a slower portion coupled with a quick section. No. 3, in C minor, took more than a month to compose, dated from 3 December 1886 to 12 January 1887. With a chordal texture spread over the entire keyboard,