Glenn Stone is a Yamaha engineer who contributed to both the FM synthesis era and the subsequent SY series of affordable digital synthesizers that extended Yamaha's market reach into home and project studios.

Stone worked on the DX7 during Yamaha's breakthrough period, helping refine the implementation of FM voice architecture that powered countless hit records. He later contributed to the SY series — instruments that offered simplified digital synthesis and preset libraries for musicians transitioning from analog to digital keyboards.

His career reflects Yamaha's strategy of tiered product lines: flagship professional instruments alongside accessible models that introduce the company's technology to broader audiences.

Notable products: Yamaha DX7, SY series.