Regarding the viola d'amore Schorn (Leidolff), Museum Salzburg

To judge by the workmanship, the carved head and the overall appearance, this beautiful viola d'amore, although bearing the label of Johann Christoph Leifdolff, was most likely built by Johann Schorn in Salzburg around 1700. The instrument has been preserved in its original condition, including the bridge, all of the tuning pegs, perhaps even the tailpiece. Some of the bass strings appear to be original as well, and will be submitted for examination by string makers.
While still living in Innsbruck, Johann Schorn (1658-1718) received commissions, as had Jakob Stainer somewhat earlier, for instruments from the Archbishop of Salzburg, Max Gandolph von Kuenburg (1668-1687), an enlightened aristocratic clergyman, generous patron of the arts, whose ambitious programmes transformed the city into a center for Baroque art, architecture and music of unparallelled brilliance. It was he who summoned Heinrich Ignaz Franz Biber and Georg Muffat to his service. On the recommendation of the Capellmeister Matthias Biechteler (ca. 1670-1744) Johann Schorn was appointed Court Violin Maker (Hoff Lauten- und Geigenmacher) in 1713, transfering his workshop to Salzburg. The influence of his Innsbrucker colleague, Jakob Stainer is so evident in Schorn's works, that his violins could easily pass for that maker's creations. His sons, Johann Paul and Johann Joseph, maintained the very high quality of violin making in Salzburg into the 18th Century.
Working together with the suggestions of Heinrich Biber, Johann Schorn may be rightfully credited with having invented the viola d'amore. Indeed his instruments may be considered the finest of them all. One of his violas d'amore is to be found in our collection. Although bearing the label of Johann Christoph Leidolff, that viola d'amore could hardly be by anyone else but Johann Schorn. The carved head of a blinded Cupid and the decorations on the rear of the peg box are identical to those found in the two violas d'amore known to have been made by Schorn now preserved in the Museum in Salzburg.
Wolfgang Amadeus Mozart played on a Johann Schorn violin. Ludwig van Beethoven owned a Salzburg violin, at present in the Museum in Bonn, which, although bearing no label, could very well be an instrument of this master or one of his sons.