Why did Beethoven write an A?

[Enrique]

In the 3rd mvt of Beethoven's Fifth Symphony, the trio begins like this:


Six bars later comes the second entrance of the theme, in violas and fagots, a fifth above:


The question is: why is the first note of the second entrance an A and not a G. Is not this an irregularity? I could add, why the C sharp instead of C natural.

[Peter]

I always think the best answer to something like that is to play it both ways - to me Beethoven's solution is far more effective. I think he is trying to suggest the tonality of D, and A (being the dominant of that key) is more emphatic. A mediocre composer probably would have provided a mere transposition, a genius something else!

[Sorrano]

Sequences are a common tool used in developing an idea; as each iteration is higher than the previous it does add a bit of excitement and energy, giving music a feeling of direction. As Peter mentioned, it also creates tonal shifting.

[Enrique]

I see the point of Peter, Sorrano. But it is not a mere sequence. This supposedly is a fugato. Plus, it's the only instance were this happens. In all the following entrances in the dominant Beethoven does it the normal way. I always thought this was odd and, surely, it must have been commented many times. This could be an example of his not being particularly respectful of the rules of counterpoint.

[Peter]

I see the point of Peter, Sorrano. But it is not a mere sequence. This supposedly is a fugato. Plus, it's the only instance were this happens. In all the following entrances in the dominant Beethoven does it the normal way. I always thought this was odd and, surely, it must have been commented many times. This could be an example of his not being particularly respectful of the rules of counterpoint.

Don't forget there are two types of fugal answer - real and tonal where the intervals are adjusted and I think Beethoven did that here to emphasise the shift to D major.

[Enrique]

Yes, although he never settles the tonality at D. I'll try to learn about the tonal answer. Well, glad to have got some answers about a point that always aroused my curiosity.

[Sorrano]

Yes, although he never settles the tonality at D. I'll try to learn about the tonal answer. Well, glad to have got some answers about a point that always aroused my curiosity.

Could that be a secondary dominant to G? Inasmuch as the codal emphasis of that phrase is G Major, the dominant, it would stand to reason that this is simply a secondary dominant. The C# in the measure quoted plays a role in alluding to a dominant of the D Major, which is the dominant of G Major. In looking at the score I realize now that I was totally off base on the sequence idea; this looks more canonical in the brief excerpt that leads to the fugal part.

[Enrique]

Could that be a secondary dominant to G?

It certainly is, I think. There is also G#, implying dominant of dominant of G.