Even though Johan Svendsen (1840–1911) was one of the most celebrated Norwegian composers and conductors of his time, the knowledge of exactly what he wrote has been lacking. The first part of this article describes Bjarte Engesets work on a new and detailed thematic catalogue, and covers several new findings that update the worklist of the composer. Less than one third of Svendsens works are available from publishers today, so there is a clear need for a modern complete practical/critical edition (JSV). Such an edition should also use the possibilities of the internet and modern computer technology. A closer study of the Svendsen-sources shows that the manuscripts often have a special significance. Many of the old printed editions do not coincide with the manuscripts in important details, and there are several arguments supporting the use of some of the manuscript-variants in modern performances. Some of the early manuscripts also have quite different, interesting versions of the works. Several particular editing problems related to Svendsens works are discussed: staccato markings appearing only at the start of sequences, the ambiguous meaning of staccato dots in abbreviated notation, etc. Johan Svendsen orchestrated with much subtlety and detail, so a thorough analysis of his use of dynamics, articulations and phrasing slurs is fundamental to the editing process. Especially in the cases where the editor is tempted to make additions to the score by analogy, such an analysis can prevent a modern edition from neglecting the subt-lety in this composers use of instruments.

Keywords: Work, catalogue, editing, source, filiation, style