Another fugue by Mozart that features counterpoint at the tenth is the infamous "Kyrie Eleison" from his Requiem. To top it all off in the most positive sense, it is a vocal fugue.
Interestingly, Mozart's subject can be interpreted as a recomposition of Bach's C major fugue subject from the WTC I, with its building blocks in reverse order! Mozart's subject ends with the ascending tetrachord 1-4 and subsequent descent to E, while in the middle both subjects have the same ascending 4ths/descending 5ths sequence. Finally, if we take the closing G A G F E from Bach's subject and reduce out the A neighbor tone we get G (dotted 8th) F (16th) E, from which by rhythmic augmentation to double note length we get the beginning of Mozart's subject.
The cadence in F reminds me of a question I had some years ago that I haven't answered. We begin to learn about fugue and are taught the introduction and then that rest of the fugue alternates exposition and episode, that not all fugues do this, etc... but that the basic model is modulating episodes that lead to entries in related keys. Then we are told that this is "Bach style," only Bach did this, other Baroque composers did not. Other fugues of the time do not modulate, generally feature only entries in the tonic and dominant. We look at some fugues by Pachelbel, for example, and this does seems to be true. Someone asks what are "inventions" and someone answers Bach made this up, they're like fugues but the answer doesn't come at the fifth, it comes at the octave or unison, but then we hear in some Early Music Sources video that all this was thought of as "fuga" long before Bach, that originally fuga could be imitation at the unison, fifth, or fourth. (Trust me, I'm getting to my question.) So Bach fugues were "fuga," but so were his inventions... it was not some new thing, it was all "fuga." But what the way in which we were told his fugues were different, what about this question of modulation and entries in related keys? Bach was weird? Modulation was "not the norm" at the time? My question was where did this come from. There is another Baroque form, lets call it variations above a ground. I was playing the Telemann Flute Fantasias and the Allegro in 5 has variations over a ground, but it changes keys. The ground is introduced in C, but then there is a sequence, and the ground comes back (actually in an upper voice, so maybe "ground" is even not right but,) it returns in A, before another sequence brings it in in yet another key. My teacher called it a "modulating chaconne." It's as if the story people were telling me about what Bach did to the fugue, Telemann did to variations over a ground here. This is done with things like Rondo too, which also seems related. I watch videos on period improvisation and get the idea you play your theme and then you make a sequence in order to modulate and bring your theme back in related keys, just kind of,... simply to have something to do, so your improvisation fills space, stays interesting, so you have a plan and you don't die on the stage. I understand fugues were improvised in this way. Was this idea of modulating to freshen the palate just a way to expand the form and fill more space with it, a formula for improvisation so the performer would have something to do? I was looking for the origin of these ideas. I wanted to know who wrote the first modulating fugue. What was the first example of the subject entering in something other than the tonic or the dominant? Did people think Bach was weird for doing this, or Telemann in the Fantasia? I don't think these things popped up out of nowhere. So here, Fux's fugue has entries in D and A, none in F. But, first the imitation at the 10th you showed kind of feels the counter subject suggests F, and then we have cadence on F. Not an entry (yet?) but a cadence. Are these things related?
There’s a lot here so I’ll try to take this piecemeal. Firstly, the idea that a piece’s title should indicate it’s form is largely a 19th century concept. 18th-c titles and earlier indicate something about the piece, but not necessarily its form or technique. Bach titled many of what we would call his fugues “fugue,” but also “invention,” “sinfonia,” “ricercare,” “contrapunctus,” “gigue,” “toccata,” “fantasia,” etc. Mozart’s Rondo k.485 is a sonata form, but he called it a rondo! These things weren’t fixed in stone until the textbooks came along. “Fuga” in the oldest sense simply indicated an imitative texture, most typically at the fifth but other intervals were possible. By the time of Marpurg, fugues at the octave or at other intervals were rare enough that he added a qualification to their name. If I remember correctly he called Bach’s C major invention a “fugue at the octave” (but not all the inventions are fugues either, like the E major). Bach likely chose the Latin title “Inventio” in reference to the first canon of classical rhetoric, which is about forming ideas and materials. They are didactic pieces meant to teach contrapuntal techniques rather than form (distributio) or style (elocutio). So the fact that they don’t have a consistent form or style is expected. As for modulation, I have no idea when the first modulating fugues were written. But it is fair to say that Bach’s music and the music of his contemporaries feature more clearly articulated modulations than most music prior, and this is true in all forms, not just fugue. Comparing Bach to his predecessor Buxtehude is probably where I would go with this question.
@@JacobGran Thank you for the detailed response. I have looked a bit into Buxtehude, but could do more. This is similar to what I've heard that modulation was "not the norm" but not that it literally started with Bach, so I'll still be on the look out for the exceptions.
