This revised edition was prepared after comparison of all manuscript sources that could be found with the last printed edition. The sources included the first sketch, two full score manuscripts (one partly by a copyist, a photocopy of the former, with autograph changes and last page, used for engraving the first edition) and a copyist's copy of the parts, with additions in the composer's hand. The previous edition contained very few errors. The corrections concern mostly a few dynamics, beaming, precision in dynamic or tempo changes, etc. (P. Bartók)