This is a vintage late-1970s Yamaha electric organ that I played at a jam session yesterday evening. I am not sure of the exact model, but I think is a B40 from 1977.
Organs can be a bit of a challenge to play if one is trained on piano and synthesizer. Basically, I just try to find a few settings that work and stick with them. Nonetheless, it was a good session, with talented drummers including one out-of-town visitor. The only harmonic instruments were organ and bass guitar, so essentially we were just a giant rhythm section. And we were able to get some interesting rhythms, including a 6/4 version of John Coltraine’s Equinox, and an extended minor blues that moved freely among different rhythmic styles and pulses while maintaining a beat.