'The Dark Side Of The Moon' (1973). The concept of this cover, according the artist Storm Thorgerson, was to try and connect with Pink Floyd's live shows; "famous for their lighting, ambition and madness... hence the prism, the triangle and the pyramids. It all connects, somehow, somewhere." Thorgerson's designs can be seen in his new book, 'Mind Over Matter 4 - The Images Of Pink Floyd' and at London's OXO Gallery from July 24 - August 10.