Bernhard Ziehn, insegnante e teorico americano d'origine tedesca (Erfurt, 20-I-1845 - Chicago, 8-XII-1912). Formatosi nel Lehrerseminar di Erfurt, dal 1865 al '68 svolse attività didattica a Mühlhausen, quindi emigrò in America e si stabilì a Chicago dove, dall'autunno del 1868 fino al 1871 insegnò tedesco, storia, matematica e musica nella German-Lutheran School. Dal 1871 si dedicò all'insegnamento privato, al quale affiancò un intenso lavoro di teorico musicale. Assai stimato da F. Busoni e da molti altri, fu invece in polemica con H. Riemann.
SCRITTI: «System der Übungen für Clavierspieler» (Amburgo, 1876)« Lehrgang für den ersten Klavierunterricht, 2 voll. (ivi, 1881), Harmonie- und Modulationslehre (Braunschweig, 1888; edizione ampliata in inglese come «Manual of Harmony, theoretical and practical» , Milwaukee, 1907); «Five-and, Six-Part Harmonies (Berlino e Milwaukee, 1911); «Canonical Studies. A New Technic of Composition» (ivi, 1912). Inoltre articoli e saggi vari in periodici e giornali (una raccolta a cura di J. GOEBEL è stata pubblicata col titolo «Gesammelte Aufsätze zur Geschichte und Theorie der Musik» , Chicago, 1927, e un'altra, col titolo «Canonic Studies» , New York, 1977). [DEUMM]



Ziehn came from Germany to the United States in 1868, eventually becoming a private music teacher and theorist. His name is especially associated with the technique of symmetrical inversion, which he detailed in his «Canonical Studies: A New Technic in Composition» (1912).35 This technique is featured in the «Intermezzo» of the Fantasia contrappuntistica, where Busoni presents the B-A-C-H theme in the form of a canon at a distance of a half note, with the right hand playing the theme doubled in sixths and the left hand doing likewise in thirds. Busoni reproduced this ten-measure passage in a substantial discussion of inversion appended to his edition of the Prelude and Fugue in D-sharp Minor (no. 8) from Book 2 of the «Well-Tempered Clavier» .

During the first half of January 1910, Busoni met Ziehn and his pupil Middelschulte in Chicago and immediately wrote for the Berlin periodical «Signale» für die musikalische Welt an essay about the two men who practised an «old gothic art in serious stillness, gazing inwards.» He concluded: «[Ziehn] is a theorist who points to the possibility of an undiscovered country and educates Columbuses. A prophet through logical conclusions. In particular, he stands alone with regard to harmony... These are the Gothic masters of Chicago, who practise a precious, great, and refined art, if not a completely alive one, in serious quietness.»
During their discussions about counterpoint, Ziehn showed to Busoni how Bach, in order to create a quadruple fugue, would have combined the initial theme from the Art of Fugue with the three themes for the triple fugue. In a note appearing on page thirty of the Grosse Fuge, Busoni wrote, «I am indebted for the present combination of the chief theme from the 'Art of the Fugue' with the three preceding subjects to the studies of Mr. Bernhard Ziehn of Chicago.»
Indeed, in January 1910, the composer wrote to his wife that he was «studying counterpoint again, for which Chicago has greatly stimulated me.» Ziehn's Canonic Studies were published in 1912, shortly after the author's death. Busoni received a copy of the 210-page book from Ziehn's wife with the following inscription: "Herrn F. Busoni zum freundlichen Andenken an Bemhard Ziehn von Emma Ziehn.» Busoni had leamed of Ziehn's death through Helen Luise Birch, an American friend to whom he was to dedicate in 1915 his «Indian Diary» , BV 267. Birch wrote to him that, when ordering for herself a wreath for Ziehn's grave, she took the liberty of ordering another having Busoni's name on it.
[ROBERGE, «Busoni, Chicago...» , pp. 311-312]