Jon Lord was a master on the Hammond B3, he could play rock organ like no one else. RIP.
Because of Jon Lord (and Garth Hudson), I once had possession of a B3 for a few months a about 30 years ago. I couldn't anything on it that sounded remotely musical, but I was able to trade it straight up for a Honer clavinet and a Wurlitzer electric piano. I sucked on both of those too.