From WILL - Classics of the Phonograph -

Composers As Interpreters of Their Own Works

Many composers have thought that they were the best interpreters of their own works. Many conductors and critics have not quite agreed. Whoever has the better argument, there is one thing to be said for the composer as interpreter: we are hearing the music more or less as he or she intended it to sound. We'll sample such composer/conductors as Darius Milhaud and composer/pianists as Erno Dohnanyi.