The Yamaha DX7 is a synthesizer manufactured by the Yamaha Corporation from 1983 to 1989. It was the first successful digital synthesizer and is one of the bestselling synthesizers in history, selling over 200,000 units. In the early 1980s, the synthesizer market was dominated by analog synthesizers. Frequency modulation (FM) synthesis, a means of generating sounds digitally, was developed by John Chowning at Stanford University, California. FM synthesis created brighter, "glassier" sounds, and could better imitate acoustic sounds such as brass. Yamaha licensed the technology to create the DX7, combining it with very-large-scale integration chips to lower manufacturing costs. Its preset sounds became staples of 1980s pop music, used by artists including A-ha, Kenny Loggins, Kool & the Gang, Whitney Houston, Chicago, Phil Collins, Luther Vandross, and Billy Ocean. Its piano sound was particularly widely used, especially in power ballads. Producer Brian Eno mastered the programming and it was instrumental to his work in ambient music. 61 KEY KETBOARD, SOFT CARRY CASE, 3 DATA CARTRIDGES