The SiON mainly consists of 3 parts, the Synthesizer, Sequencer and Effector.

- Synthesizer Part

The SiON's software synthesizer is an extention of the FM sound chip YM2151(a.k.a. OPM)'s emulator. Currently, SiON includes 5 types of sound modules.

• Extended Emulators of FM sound chips; The emulation code is based on the time-proven emulators, MAME, fmgen and x68sound.dll. And the outputs of various sound chips (OPM,OPNA,OPL3,OPX,MA3) are reproducible by giving same parameters of actual equipments.
• Simulator of PSG sound chips and wave memory sound chips; The SiON's Extended FM synth can simulate various PSG chips (like AY-3-8910, DCSG, 2A03 or SSG) and wave memory sound chips(SCC, C15 or GameBoy).
• Physical Modeling Guitar synthesizer; SiON also includes Guitar Physical modeling synthesizer based on the Karplus strong algorithm.
• PCM sound module; The SiON handles MP3 sound (Sound Class) as a PCM sound modules source wave. This provides the musical sequential handling of MP3 file sound.
• Analog "like" synthesizer; The voices can be modified by traditional "2-oscillators VCO, VCA and VCF with ADSR envelop" type parameters. And you can apply all wave shapes of SiON as the oscillator output.
  

And you can modify the output from these sound modules by low-pass filter with ADSSR envelop, ring or sync modulation, pitch/amplitude modulation.

- Sequencer Part

The SiON uses Music Macro Language (MML) as a musical score data. The MML is a simple powerful language to represent musical sequence. For example, below MML represents “the ABC song”.

The MML reference manual, the MML editor, and you can read MMLs of various great musics in MMLTalks (click rightmost button in song title).

- Effector Part