Arnold Schönberg is the central figure in the musical world of this century. His musical significance was already apparent during his life-time, but his posthumous influence has increased immensely. His work paved the way for ground-breaking changes in musical perception. This complete edition aspires to be equally indispensable for research as well as for performance. The edition is published in two series: series A in folio format contains all completed works, all piano scores prepared by the composer himself and all unfinished works suitable for performance, also fragments (large scores) which are better suited to be printed in such a format. Series B, in quarto format, contains early versions, sketches, ideas and fragments as well as genesis and a Critical Commentary.