Nikolai Diletsky, born around 1630 in Kiev, was a prominent music theorist and composer during the late 17th century. He was a significant figure in the introduction and development of Western European musical theory in Russia. Diletsky received his musical education in Warsaw and Vilnius, where he also taught church singing and served as a precentor. His most influential work, "Grammatika musikiyskago peniya" ("A Grammar of Musical Singing"), was the first comprehensive treatise on music composition in Russia, introducing Western musical concepts and the circle of fifths.

Diletsky's contributions were pivotal in establishing partesny singing (part-singing) in Russia, and he founded a compositional school that influenced many, including Vasily Titov. His compositions include works for four and eight voices, such as "Sluzhba" and "Voskresenskiy kanon." Diletsky's treatise and compositions played a crucial role in shaping Russian church music, and his ideas on polyphony and ensemble music were illustrated with examples from leading Polish composers.

He lived in various cities, including Vilnius, Smolensk, and finally Moscow, where he spent the last years of his life until his death around 1680. Despite the scarcity of detailed biographical information, Diletsky's legacy in music theory and composition remains influential.