This piece is available in two different versions: for prepared harp solo or prepared harp with computer playback. You can hear both versions here - - - - - - - ->
The Curl-up, as seen in the print House of Stairs, is a curious little animal that Escher created out of his dissatisfaction with the fact that in nature there are no wheel-shaped animals which are able to move by rolling. This piece was conceived as the music for an imaginary nature documentary about this odd creature (which is a sort of cross between a lizard and a centipede), and portrays various aspects of its locomotion and habits before climaxing in a soaring melody depicting its mating ritual (”nothing special”, according to Escher). To enhance the quirkiness of its sound, the harp is prepared (à la John Cage's prepared piano) by placing little bits of putty and alligator clips on some of its strings.