The sixith volume to appear in the new Chopin edition is the Impromptus, edited by John Irvine. The most famous of these pieces is , of course, the so-called "Fantaisie-Impromtu".Because Chopin suppressed its publication during his lifetime for some reason, this work has suffered more than most from the editorial 'free-for-all' that disfigured most Chopin publishing for at least a century after his death. In the last fifty or so years, propelled by Arthur Rubinstein's discovery of an autograph score, the situation has improved markedly, and the new Peters volume is able to reflect the very latest source scholarship, both for this and the other Impromptus.