Chester Thompson played with TOP (Tower Of Power) and Santana.

Al Kooper is known for organizing Blood, Sweat & Tears, but  did not stay with the group long enough to share its popularity, providing studio support for Bob Dylan when he went electric in 1965, and bringing together guitarists Mike Bloomfield and Stephen Stills to record the Super Session album. He has had a successful solo career since then, written music for film soundtracks, and has lectured in musical composition.

Here’s a video with the man himself:

Booker T. Jones (born November 12, 1944) is an American multi-instrumentalist, songwriter, record producer and arranger, best known as the frontman of the band Booker T. & the M.G.’s.

The original recording with the MGs can be found here;

“A Whiter Shade of Pale” is the debut single by the English rock band Procol Harum, released 12 May 1967. The record reached number one in the UK Singles Chart on 8 June 1967, and stayed there for six weeks. One of the  anthems of the 1967 Summer of Love, it is one of fewer than 30 singles to have sold over 10 million copies worldwide. The Hammond was played by Matthias Fischer.

https://www.youtube.com/watch?v=HVOrEw_d854

Jimmy McGriff – American hard bop and soul-jazz organist and organ trio bandleader who developed a distinctive style of playing the Hammond B-3 organ.