It is not widely known that the original version of Bartók's Sonata for solo violin differs in a number of details from the published edition, and in the finale significantly so. A complete list of the changes, which include many details such as bowings, fingerings, expression marks and caesuras, cannot be given here, nor would it serve any very valuable purpose, since the editing of the work for performance and publication by Menuhin, who had commissioned it, was done in close consultation with the composer. Some of the alternatives were indeed suggested by Bartók from the beginning, and were already jotted down on a spare half-page at the end of the manuscript when it was first sent to Menuhin. This is true, for instance, of the changes in the finale, although unlike most of the others, these, while arising out of considerations of practicability, are of very much more than mere practical importance. For the original text of the finale provides the most conspicuous example in all Bartók's works of the use of microtones.