The Roland System 100 Model 101 is a classic all analog monophonic synthesizer very similar to the popular SH series released by Roland. The 101 is foundation for the System 100, which is comprised of this model 101 synthesizer model, a sequencer, mixer, speakers, and a synthesizer expander modules. Like many of Roland's mono-synths, the 101 features a 37 note keyboard, VCO, LFO, VCA, VCF with high and low pass, and ADSR and noise in a small package. a simple but classic synthesizer with the trademark Roland sound