Nach Bach

Nach Bach (German for "After Bach", subtitled Fantasia for harpsichord), is a composition for harpsichord or piano by American composer George Rochberg, written in 1966 and dedicated to his friend Igor Kipnis, who premièred the work in Annenberg Auditorium at the University of Pennsylvania on 27 January 1967.
Rochberg composed this piece while still serving as chairman of the music department at the University of Pennsylvania. He had just abandoned serialism three years previously in 1963, the year before his father died, in the spring, and in November of the same year his teenage son, Paul, died because of brain tumor. The composer said it was after his son died that
He also said he had found serialism to be a style incapable of expressing "serenity, tranquility, grace, wit, energy and perhaps most importantly, joy". His last serial work was the Trio for violin, cello, and piano, written in 1963.
Rochberg composed the work at Tanglewood in the summer of 1966, on a commission from the harpsichordist Igor Kipnis. At the time, Rochberg knew virtually nothing about the technical problems of the harpsichord, so before setting to work had a long discussion with Kipnis who demonstrated the use of pedals, the attack and timbral characteristics of the instrument, which enabled the composer to incorporate every possible color combination available on Kipnis's custom-built instrument into the structure of the piece. The manuscript score is dated July 6, 1966, and at that point was designated only for the harpsichord. The score was revised for publication, to include registration markings for the harpsichord added by the dedicatee, Igor Kipnis, and accommodations for performance on the piano, including dynamic markings, indications for pedaling, and ossia passages (on pages 4.1, 4.2, and 8.2) in which some notes are to be played an octave higher on the piano than in the version for harpsichord.
This work is in free form, like many other fantasias, with long sections with durations in unmeasured notation. The composer describes this form as "open, asymmetrical and progressive, i.e., non-repetitive, and so akin, in spirit at least, to the old 'fantasia' idea of Bach and Mozart". In the score, according to the composer, passages marked in boxes are direct quotes from J. S. Bach's Partita No. 6 in E minor, BWV 830, and should be played as dramatic "inserts". In addition to these direct quotations, all of which occur in the second of its five main sections, there are many non-literal quotations and pitch segments derived from Bach's composition. There is also a quotation from a Brahms Intermezzo on the last page.
The general texture of the work is freely atonal, with rhythms written in indeterminate notation. One of the most striking features of the work is the contrast between this predominant texture and the quotations from Bach. A free-form composition with an improvisatory character, the work nevertheless falls into five large sections, with a transitional passage between sections two and three. The sections are discriminated by the use of strong cadences, long pauses, and changes in texture, density, tempo, mood, and dynamics. Dissonances are also used to differentiate the sections.
Although it does not employ twelve-tone technique, several twelve-tone sets occur in the piece, including one that opens the work: B♭, E, B, C♯, D, C, E♭, F, G♭, A, A♭, G, which divides into a pair of [0, 1, 2, 3, 4, 6] hexachords. Many of the main pitch elements of the piece are derived from this set. Three further twelve-tone sets occur in the second main section, and two in the third.
Performed on harpsichord
Performed on piano
Sources