Moog synthesizer (pronounced /ˈmoʊɡ/ MOHG; often anglicized to /ˈmuːɡ/ MOOG, though Robert Moog preferred the former) may refer to any number of analog synthesizers designed by Dr. Robert Moog or manufactured by Moog Music, and is commonly used as a generic term for older-generation analog music synthesizers. The Moog company pioneered the commercial manufacture of modular voltage-controlled analog synthesizer systems in the early 1950s. The technological development that led to the creation of the Moog synthesizer was the invention of the transistor, which enabled researchers like Moog to build electronic music systems that were considerably smaller, cheaper and far more reliable than earlier vacuum tube-based systems.