The concert of the Philadelphia Musical Fund Society on April 29, 1829 featured a guest appearance by Boston’s Mr. Widtl in a Horn Solo by Düring.
[Musical Fund Society of Philadelphia, Scrapbook.  See also Jeffery L. Snedeker, 1997, p. 164ff, T
he composer is possibly Heinrich Vollrath Düring (1752-1791), stepfather and first teacher of  composer Friedrich Witt (1770-1836), but more probably Witt’s half brother,  Johann Georg Heinrich Düring, who was also an accomplished composer. At his death he was noted as a musician of the  highest merit (“hochverdienter Musiker”) in Frankfurt am Main.  See Ernst Häußinger, “Der Komponist Friedrich Witt aus Niederstetten”, Württembergisch Franken. Jahrbuch des Historischen Vereins für Württembergisch Franken. Band 57. Schwäbisch Hall, 1973, S. 137-142, 
http://www.guenther-emig.de/witt/haeussinger.html]