Uploaded July 2012 | Updated September 2026, 1 week ago
The Pro-Soloist Mk I has mostly black switches and white lettering.
A few notes in the bottom octave (C, C#, E, F#, A#, B) randomly skip octaves when struck multiple times. This may be an idiosyncrasy of this keyboard or it might need adjusting somehow.
The Pro-Soloist Mk I has mostly black switches and white lettering.
A few notes in the bottom octave (C, C#, E, F#, A#, B) randomly skip octaves when struck multiple times. This may be an idiosyncrasy of this keyboard or it might need adjusting somehow.


![1972 MATTEL Optigan Program Disc: Bluegrass Banjo [70201]
Sounds from Optigan Music Maker. Get the Optigan app to hear better samples and it works just like the real thing. You can even play the virtual discs upside-down (backwards). Or, get them at optigan.com. 1972 MATTEL Optigan Program Disc: Bluegrass Banjo [70201]](https://i.ytimg.com/vi/YEv48dv8ZlE/mqdefault.jpg)







