Johann Sebastian Bach: Musical Offering, BWV1079

Program Note

“Regis Iussu Cantio Et Reliqua Canonica Arte Resoluta” 
(At the king’s command, the theme and its solution resolved in canonical manner)
From the Berlin newspaper Spenersche Zeitung, May 11, 1747:
"We hear from Potsdam that last Sunday, May 7, 1747, the famous Capellmeister from Leipzig, Mr. Bach, arrived with the intention of hearing the excellent Royal music. In the evening, at about the time when the regular chamber music in the royal apartments usually begins, his Majesty was informed that Capellmeister Bach had arrived at Potsdam and was waiting in His Majesty’s antechamber for His Majesty’s most gracious permission to listen to the music. The King immediately gave orders that Bach be admitted, and went, at his entrance, to the so-called Forte-and-Piano, condescending also to play, in person and without any preparation, a theme to be executed by Capellmeister Bach in a fugue. This was done so happily by the aforementioned Capellmeister, that not only His Majesty was pleased to show his satisfaction, but also all those present were seized with astonishment. Mr. Bach has found the subject propounded to him so exceedingly beautiful that he intends to set it down on paper in a regular fugue and have it engraved on copper."
Bach did just that, but in attempting to save paper, the work’s various sections were published on sheets of different sizes, confusing many as to the sequential order, if any.
The Musical Offering is time-conscious, expressing a historical perspective unusual for Bach and his era. Perhaps he was, in his years of semi-retirement, contemplating the work of past and future generations of Bachs. We start two hundred years earlier, as it were, in the Renaissance, with an old style three-voice fugue, then called Ricercar, which Bach expanded by means of modernistic keyboard improvisations, serving as episodes in the fugue. Progressing through the contrapuntal playground of the canon, the art of setting a tune against itself, we arrive in the 1740s with perhaps the Baroque’s greatest trio-sonata. This four-movement work explodes into Bach’s present and immediate future: the florid and improvisatory, personal and rhetorical, virtuoso and democratic writing of his own times and the sensitive, fragile, pre-classical, pre-romantic manners of his son’s generation. The first part of the royal theme appears in the bass line (cello and harpsichord) at the opening of the first movement and again later (still in the bass) split up into many fragments. In the second movement, the violin and flute open with an ornamented version of the royal theme played backwards. Four times during the movement the royal subject (forwards, in the bass) may be heard simultaneously against the ornamented version (backwards, in the violin or flute). But only once are the roles reversed (the royal tune in the violin above the backwards ornamented version in the bass): this event occurs at the exact mathematical (time) center of the Trio Sonata, which in our version creates the center point of the entire Musical Offering. It is an eclipse-like moment, comparable to little else in the history of music. Then moving backwards in time, stylistically, through Bach’s Canonic Elaborations, we arrive at the mighty six-voice Ricercar, a masterwork even among Bach fugues, which meshes the severity of a completely de-ornamented style with the rich sensuality of a close ensemble.
—Kenneth Cooper, 2014