The series that analyses the durability of pop songs looks at Procul Harum's A Whiter Shade of Pale, which, in the summer of 1967, intoxicated the world with its psychedelic mix of swirling Hammond organ, surreal lyrics and harmonies borrowed from Bach. The song's lead vocalist, Gary Brooker , traces the song's evolution, with help from mobile DJ Dave Jansen and guitarist Nick Bell. Producer Alan Hall