I have a vintage Korg Mono Poly Synthesizer Synth in very good condition for its age. All the keys work and it sounds out of this world. 4 oscillators of tuning weird madness. Has a strange but nasty filter that is very unique. Same exact filter as the Korg PolySix. The Sync/S&X/ X-Mod really make this sound very interesting. Plus the Excellent Ring Modulation will go crazy. Those 4 oscillators stacked make this thing sound absolutely huge has a great Arpeggiator too. You can go from Pop to synthpop then to nasty industrial in seconds. You could do alot of weird horror movie stuff with this as well. Very fun and very unique. One of the most underrated synths made. These are becoming quite rare. $1600