Kurzweil Music Systems is a company that produces electronic musical instruments for professionals and home users. Founded by Ray Kurzweil, a developer of reading machines for the blind, the company made use of many of the technologies originally designed for reading machines and adapted them to musical purposes. They released their first instrument, the K-250, in 1983, and have continued producing new instruments ever since. The company was acquired by Young Chang in 1990, though recent financial problems put the company's future in doubt.

The company's flagship line of synthesizers, the K2x series, began to make real headway with the K2000, which introduced the company's acclaimed VAST (Variable Architecture Synthesis Technology) engine. Throughout the 1990s, updates and upgrades to the K2000 (and eventually its sucessors, the K2500 and K2600) ensured that the K2x series was regarded as one of the most powerful and best-sounding synthesizers/samplers available.

Kurzweil's products are said to be of high quality, but their high pricing in a competitive market has prevented Kurzweil from gaining widespread adoption.

Competitors include Korg and Roland Corporation.