Yamaha PSR-4000

The Yamaha PSR-4000 is a professional-level arranger keyboard released by Yamaha in 2000. It is a 61-key keyboard with a wide range of features, including a built-in sequencer, a variety of voices and styles, and a powerful sound engine. It has been used by many professional musicians, including jazz keyboardist Herbie Hancock, and has been featured in many live performances.

The PSR-4000 works by allowing the user to create and arrange music using its built-in sequencer. It has a variety of voices and styles, including piano, organ, strings, brass, and more. It also has a powerful sound engine that allows the user to create their own sounds and effects. Additionally, it has a variety of features, such as a built-in mixer, a variety of effects, and a built-in metronome.