DAILY DOSE of BEETHOVEN (July 7, 2020)
CPE Bach tells us that although a “Fantasy” requires a thorough knowledge of harmony, a written-out work, such as a “Sonata”, requires a far more comprehensive knowledge of composition. Mozart seems to challenge that notion by finding an even higher degree of rigor in an improvisation than in a sonata.
Today, we examine key transitions in the rest of Mozart's K. 475 “Fantasy”. Again, we provide Mitsuko Uchida’s performance with score:
1. A quick review: Mozart changes Bach’s 5-note theme from the “Musical Offering”: C Eb G Ab B, by adding two tones—F# and another C, to a 7-note theme: C Eb F# G Ab C B. Both of these changes make an important difference. The last four tones, G-Ab C-B, give us mirror image half-tone motifs.
Mozart employs Bach's descending "chromatic" line brilliantly by changing only one note every measure, and placing it in the bass line, so that it determines the harmonic ordering, rather than function as a melody. That descending bass line does not stop at G (the dominant of C Minor), but in measures 15-17, comes to rest on Gb-F#.
This is a turning point in the work. The tritone, or "Lydian" interval, which divides the C octave exactly in half (at F#), has been introduced both in the first-measure theme starting from C. and the bass line starting from C. Mozart is investigating a different generating principle of the musical system.
2. For the next few measures, Mozart plays around with B Minor and Major, alternating D natural and D #. The tone F# always bears a crucial role. After a lot of questions, that tone F# is isolated as the fifth of B Minor. At measure 24, F# repeats, alone, then becomes the third of D major. That is a magical, but lawful moment! It emerges between 2:50 and 3:03, in this recording (right around the repeat sign, or measures 22-26 in the score.)
3. After a long melodic section, the half-tone motions reappear at about 5:33. We hear E to F in the bass again and again. We are now in A Minor, and E to F corresponds to the same interval as G to Ab in C Minor. A few measures later, at 5:43, a turn marked P, on the notes A Bb G# A, A Bb G# A, reminds us again of the opening.
At 6:02, we wander into F major. It is a very simple idea. But again derives from the theme. The right hand plays on C and D, then descends to F-E. In F major, C and D are tunes 5 and 6 in the scale, and F and E are 1 and 7. That in turn, proceeds 5-6 and 1-7. The last 4 tones of the theme, G Ab C B were 5-6,and 1-7 in C Minor. The left hand also reflects it a bit.
Starting at 6:18, for about one minute, A Major change is prepared by a bass line descending in half-steps! A long “Andantino” in Bb follows, and at 9:30 climaxes in a “Piu Allegro” section reminiscent of the Bach’s “Prelude in C Minor” from the Well-Tempered Clavier, Book I. This section fills CPE Bach's recommendation that at some point the improviser proceed through a part of the Circle of Fifths. Since the days of Pythagoras, investigating that circle had been a means of trying to determine the true nature of the musical universe. Proceed as the bass line does here, G to C to F to Bb, to Eb to Ab etc. If that were done 12 times you would end up back at G.
Mozart almost does that but his concern is to lead us back to the opening. At 10:00, he continues to move through this circle, and gradually introduces more of these "Lydian" or tritone intervals. At about 10:41, a few measures before the opening returns at "Tempo Primo", he contrasts two rising tones, with two descending ones. What are they? The descending tones are C-B, and Ab-G, over three octaves! After a long pause, we feel fully prepared to hear that powerful opening once again.
But is it an exact repetition? Of course not. It's Mozart. This time though, it really does behave like C Minor and it comes to a glorious end in that key.
This “Fantasy in C Minor, K475” became the "meat and potatoes" for future composers. They all studied it. His revolutionary use of the Lydian mode will be the basis for an intense, continuous dialogue, particularly with Beethoven, who also recognized the central nature of Bach's “Musical Offering”, thus composing particularly his Op. 13 "Pathetique" Piano Sonata in C Minor, as well as his last Piano Sonata Op. 111, in which Beethoven explicitly "quotes by paraphrase" Mozart's “Fantasy” just after the famous "double trill" section.
We shall go to Beethoven’s innovation in the next days. In the meanwhile, we leave you with a seldom-heard work: the then sixteen year-old Franz Schubert's Fantasy in C Minor. See if it rings a bell!