The Yamaha PSR-S975 is an arranger workstation keyboard that combines a wide range of sounds together with powerful performance features that provide the experience of performing in a band to the solo keyboard player. Two assignable live controllers, a modulation wheel, and two assignable foot pedal inputs ensure total control over voices, styles, effects, and other functions during live performance. Fifteen new DJ Styles feature a collection of chord progressions that eliminate the need for continuous chord changes with the left hand. The sampled sounds are complimented by percussion ensembles and drums recorded by world-class musicians in studios around the globe, while a Synth Vocoder function lets the user's voice synthesize the internal sounds. A Vocal Harmony 2 system adds harmonies with control provided over the pitch, level, and number of harmonies added, ensuring the vocals are always present. The arranger includes distortion and reverb effects taken from the Tyros 5 keyboard, delivering an authentic and natural sound with effortless editing of effect parameters via an intuitive interface. The company's Virtual Circuitry Modeling (VCM) technology also simulates wah, compressor, and phaser effects at the circuit level. Sound expansion is available using the 768 MB of on-board expansion memory. And to enhance practicing and performance, the optional Yamaha Chord Tracker app for iPhone and iPad instantly identifies and extracts any chord sequence from an audio track stored on the keyboard. The Yamaha PSR-S975 includes a music rest and power supply.