The Poly line is associated with synthesizers that are capable of polyphonic sound, allowing musicians to play multiple notes simultaneously. These instruments often come with advanced features for sound design, such as layering, modulation, and built-in effects.

Polyphonic synthesizers are popular among composers and performers looking to create rich, complex harmonies or textures. Brands like Roland, Yamaha, and Sequential offer various polyphonic models, each with its own unique sound engine, making them versatile tools for live performance and studio production.