Preface on title page lists this volume as part of "Courses in Dr. Hoch's Conservatory in Frankfurt a[m] M[ain]." Title reads, "The fugues of the 'Well-Tempered Keyboard' of Joh[ann] Seb[astian] Bach in pictoral representation published as an appendix and addition to his textbook on the composition of the fugues by Iwan Knorr." Inside text is given in German, English, and French. Published in Leipzig in 1912 by Brietkopf & Härtel.