This document discusses Modest Mussorgsky's famous piece "Pictures at an Exhibition", which was composed based on paintings by Mussorgsky's friend Victor Hartmann. It provides context about Mussorgsky and Hartmann, and describes two of Hartmann's paintings - "The Great Gate of Kiev" and "The Tuileries" - that influenced Mussorgsky's composition. It also mentions that Emerson, Lake & Palmer later recreated "Pictures at an Exhibition" in a live album.