Is the S90 ES a digital piano with 88 weighted keys and the sonic flexibility of a synth or is it a synthesizer with the best piano sounds available? In fact, it's the perfect mix of both. The S90 ES has the most expressive acoustic piano sound Yamaha has ever put into a synthesizer thanks to the new multiple speed stereo sampling of Yamaha's handcrafted S700 acoustic piano, damper reverb effects, and "half damper" function. The 128-note polyphonic sound generator, based on the award-winning Motif ES (with 8 insertions, 2 separate master systems and effects) and the expandability offered by Studio Connections, mLAN and PLG guarantee the same sound power and control flexibility as the workstations of the Motif ES series. The new S90 ES is the perfect mix of synthesizer and piano.