A programme of 40-odd piano duet movements composed for teachers and students at varying stages of early progress might not appear very appealing for the hardened critic. But everything here, from the resourceful Chopsticks variations jointly composed by Cui, Borodin, Rimsky-Korsakov and Liadov to Stravinsky’s Easy Pieces and new work by Michael Blake and John Carmichael, is a gratifying listening experience, and the untainted enjoyment of Gray’s participating pupils (mostly schoolchildren) is palpable.