Okay, so when I was a kid my dad introduced me to the sound of the Hammond B3 organ via the late great Jimmy Smith.  Take a look at this video, one of many Barbara Dennerlein videos on youtube, and witness how she uses her entire body to create her incredible music.  This is just a soundcheck for a concert and the cameraman focuses on her feet when she takes off playing a bass line with them.  At around 1:20 she realizes he's filming her and she takes off.  Her improvisational creativity  is unsurpassed and is at the forefront even in this soundcheck.
http://youtu.be/ZqSBKZzCrM0