After studying music, he is first active as a flutist, in 1914 he is conducting an orchestra for the first time. After conducting in Berlin, in his home region and in Vienna. In 1925, he switches from flute to saxophone and founds his first Jazz band. Following the fad of this time, he changes his name to Lewis Ruth for the following years. After some years in Berlin, his big success, providing the orchestra for the "Dreigroschenoper" by Bertolt Brecht and Kurt Weill follows in 1928. Until 1933, Lewis Ruth Band is the name of his popular orchestra. In the following years, he again uses hie real name and also his orchestra is reformed and renamed to Ludwig Rüth Und Sein Orchester.
Due to the relationship with a jewish woman, Rüth leaves Germany in mid 1937 to South-West Africa in order to marry her. His orchestra continues to exist under his name in Berlin, but is renamed later to Hans Carste Und Sein Orchester, as the orchestra is led by Hans Carste after Rüth's immigration. Rüth himself never returns to his old profession and dies in 1941 under unclear circumstances.