Some theoreticians, however, rejected even the idea that rubato relies on accelerando and ritardando. Frequent accelerando and ritardando give an impression of rhythm that moves like a wave. The final strophe of 4 has an "accelerando" leading directly into the "vivace" of 5. Before the third theme appears, the tempo is raised with an accelerando. A frenzied accelerando played by both instruments concludes the piece. He has also helped mentor aspiring young musicians as part of the MRC's "Accelerando" program. Simpson described the second movement as 'a huge composed accelerando, but with the dynamics repressed'. The final repetition of the main theme is often played as one continuous accelerando. "Accelerando" won the 2006 Locus Award for Best Science Fiction Novel.