I saw Herbie Hancock in the late '70s, where he was performing stuff from his about to released 'Secrets' album.

Rather disappointed - to my ears he was just noodling around with various keyboards. Admittedly he had visited a shop in Denmark street (?) that afternoon and bought some instruments, so probably hadn't had much of a chance to get used to them - but it seemed to me he was just 'faffing' about.