Here is how the opening theme goes:
and here is the continuation:
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The theme is presented in four strict fugal entries. It consists of two parts: the dotted octave figure which is a kind of introduction, followed by the stepwise passage that follows. Beethoven will take that single measure motif and use it extensively throughout the scherzo. Here is a typical passage:
Sometimes, just so the players don't forget, he marks nearly every note with an "f" for "forte". That octave dotted motif is also heard frequently on the tympani--probably the first time where percussion plays a thematic role.
As you might expect, rhythm is an important structural element in the movement. It provides us with a great example of "hypermeter". Hypermeter is a term coined in the 1960s by the theorist Edward T. Cone to describe a situation where measures are grouped to create a larger scale meter. We can see this in a situation where a section ends with one or more measures rests--they are there to complete the hypermeasure:
What Beethoven is telling us here is that he is changing from a hypermeter of four measures making up one hypermeasure to three measures. In the example above, the six measures make up two hypermeasures. Later on he changes back:
The above example is two hypermeasures, each with four measures. Beethoven is calling this a "rhythm of four beats" because, at this quick tempo, each measure is a beat.
He even manages to create a "rhythmic cadence" with hemiola (grouping pairs of quarters to create half note beats). This is how he ends the scherzo and transitions to the contrasting trio which is in D major, alla breve with smooth, flowing lines. Here is that "cadence":
Then, after the trio, the whole scherzo comes back again. A truly remarkable movement based on some very simple basic ideas, with the maximum possible extracted from them. Here is the movement performed by the Staatskapelle Dresden orchestra conducted by Sir Colin Davis: