In 1877 Edvard Grieg informed his publisher that he had added “a free, second piano to several of Mozart’s sonatas.” As he later emphasised, his modernization “did not change a single one of Mozart’s notes”, but constituted “a way of showing admiration for an old master.” Grieg also intended the pieces for a duo of student at teacher; here the performers are a pianist of exceptional distinction and her legendary mentor: Elisabeth Leonskaja and Sviatoslav Richter.