Written in 2010 for the Royal Liverpool Philharmonic, Wigglesworth's nine-minute work explores the idea of perpetuum mobile (continuous movement) in seven connected, miniature inventions. A regular pulse forms the work's core, with elaborations of the central musical idea shifting constantly around it in jagged rhythms and sumptuous orchestration. The composer writes, ''The seven sections can very briefly be described thus: 1) an active, miniature 'theme and variations', 2) the juxtaposition of various fragmentary two-part inventions, 3) a tremolo string ostinato with woodwind interjections, building towards the first climax, 4) an ostinato passing between horns and muted trumpets together with a dialogue for high woodwind and low strings, 5) a very slow canon for string harmonics and pizzicato double basses, 6) a fast, one-part invention beginning with solo piccolo, and gradually leading to the second climax, 7) chorale''. This is a lively orchestral miniature which gives the impressi on of a kaleidoscope, with short musical ideas cutting across each other in quick succession.