John Douglas Lord was an English keyboardist and composer. In 1968, Lord co-founded the hard rock band Deep Purple, and he became regarded as its leader in the early years. Lord performed on most of the band's most popular songs; he and drummer Ian Paice were the only continuous members in the band between 1968 and 1976, and also from when it was re-established in 1984 until Lord's retirement in 2002. He also spent time in the bands Whitesnake, Paice Ashton Lord, the Artwoods, the Flower Pot Men and Santa Barbara Machine Head.

The Hammond organ is an electric organ invented by Laurens Hammond and John M. Hanert and first manufactured in 1935. Multiple models have been produced, most of which use sliding drawbars to vary sounds. Until 1975, Hammond organs generated sound by creating an electric current from rotating a metal tonewheel near an electromagnetic pickup, and then strengthening the signal with an amplifier to drive a speaker cabinet. The organ is commonly used with the Leslie speaker.