Which Baroque composer was known for writing single movment sonatas? 
Domenico Scarlatti: Giuseppe Domenico Scarlatti (Naples, 26 October 1685 Madrid, 23 July 1757) was an Italian composer who spent much of his life in the service of the Portuguese and Spanish royal families. Domenico Scarlatti:  He is classified primarily as a Baroque composer chronologically, although his music was influential in the development of the Classical style and he was one of the few Baroque composers to transition into the classical period.
i don't know