Prior's Piano Concerto No. 1 was premiered at the V International Piano Festival in St. Petersburg in September 2006. Prior was runner-up in the 2008 International Prokofiev Composers Competition – his Piano Concerto No. 2 "Northern Dances" was performed by the State Academic Symphony of St. Petersburg in the Great Philharmonic Hall. In 2006, Prior's ballet "Mowgli" (based on Rudyard Kipling's "The Jungle Book") was commissioned by choreographers Natalia Kasatkina and Vladimir Vassilev of the Moscow State Classical Ballet. The official premiere took place at the Kremlin Theatre in Moscow in February 2008.