I only heard about Rudolph Johnson through my teacher a few months ago. I then found three of his CD's on the Black Jazz Label: Spring Rain (his best imo), Second Coming, and Powerhouse (as a side-man with Chester Thompson of TOP fame). My favourite is his burning playing on Silvia, an up-tempo blues on Spring Rain.
I just found out today he passed away
Those recordings are from the early '70s and from what I've heard he gave up playing several years ago. However that article says he played with Ray Charles for 30 years.
Rudolf Johnson, yet another underrated player.