This Additive Synthesizer is a stand alone Music Instrument if you use it on a tablet or a phone with a touchscreen. It can also be a sound expander if you connect a PC with a MIDI keyboard by a USB cable. You can use the build in sound presets and modify them to create an endless number of new sounds. The synthesizer sound engine works on the principle of the Advanced Additive Synthesis with 4 oscillators and more than 20 sound effects and is polyphone with 16 voices.