Roland and Ketron can play 3 patterns per part (Maj / Min / 7th)
Korg it's 6 patterns for Mains, and 2 for other
Yamaha is, as Jorgen saied : you can record 16 tracks per part.
Then you decide witch track will play with witch chord pattern.
So you can for example share the drums for all patterns, but decide to record another bass track for minor chords...