Nikolai Girshevich Kapustin (Russian: Никола́й Ги́ршевич Капу́стин; born November 22, 1937 in Horlivka, Ukrainian SSR) is a Russian composer and pianist.
Kapustin studied piano with Avrelian Rubakh (pupil of Felix Blumenfeld who also taught Simon Barere and Vladimir Horowitz) and subsequently with Alexander Goldenweiser at the Moscow Conservatory. During the 1950s he acquired a reputation as a jazz pianist, arranger and composer. Thus, he is steeped in both the traditions of classical virtuoso pianism and improvisational jazz.
He fuses these influences in his compositions, using jazz idioms in formal classical structures. An example of this is his Suite in the Old Style, Op. 28, written in 1977, which inhabits the sound world of jazz improvisation but is modelled on baroque suites such as the keyboard partitas composed by J. S. Bach, each movement being a stylised dance or a pair of dances in strict binary form. Other examples of this fusion are his set of 24 Preludes and Fugues, Op. 82, written in 1997, and the Op. 100 Sonatina.