Ach, wie ist's möglich dann also known as Treue Liebe (True/Loyal Love), is a German now-traditional song. Friedrich Wilhelm Kücken (1810 - 1882), a German composer and conductor, claimed to have composed the tune, and that it was later modified "probably by Silcher" ("wahrscheinlich von Silcher her") and given the general name Thüringer Volkslied ("Thuringian folksong"). Its popularity helped Küchen get chosen for the court of Grand Duke Paul Friedrich von Mecklenburg-Schwerin. The tune is used at West Point, Lincoln University (Missouri) (Lincoln, O, Lincoln) and Wake Forest University. Marlene Dietrich sang the song and it has been used in a couple of movies.

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