The Well-Tempered Klavier, or preludes and fugues in all tones and half-tones, as well with the major third or “A, D, E”, than with the minor third, or “D, E, F”. For the use and benefit of the young musicians who want to learn as well as for the entertainment of those who are allready expert in art. - Anno 1722.
Robert Schumann took it as his motto, and Chopin said: “One can never forget it.”