Interesting, I had no idea the performances were so much slower than what Beethoven intended. And I also used to think (and think to some extent now) that it's a kind of mysterious movement. It's the only movement in the symphony that isn't so bombastic and it's pretty calm compared with the rest. Maybe it makes more sense when it's performed at the speed Beethoven wrote (I don't know as I haven't listened to such a performance I think).The metronome was newly invented in the early 1800s and at first Beethoven (and Salieri) were quite enthusiastic about it as it offered a more precise way of indicating to performers exactly the tempo the composer had in mind. In the late 18th century there were various tempi ordinari being used--that is, "standard tempos" that were widely known. Charles Rosen has an excellent discussion of this in his book on the Beethoven piano sonatas [pp 45 et seq.] But Beethoven came to understand that the metronome did not exactly solve all the problems. In a note written on the manuscript of his song "Nord oder Süd" he wrote:
100 according to Mälzel, but this must be considered applicable only to the first bars, for sentiment also has its tempo and cannot be completely expressed by this number.Ah, sentiment! The question of "sentiment" or what we might rather call "expression" applies most strongly to slow movements. The problem I see with Beethoven's metronome markings in the slow movement of the Symphony No. 9 is that the opening section, Adagio molto e cantabile [quarter note = 60] is very difficult to reconcile with the contrasting section Andante moderato [quarter note = 63]. Sixty versus sixty-three is almost no difference at all and if there is no difference, there is no contrast. So in my mind the tempo words Beethoven chose are at odds with the metronome markings. Either the Andante has to be a lot faster (which would be silly) or the Adagio a lot slower (which is the choice Barenboim and a lot of others make). It is not the crudely simplified question of either following Beethoven's metronome markings or ignoring them, it is rather a question of whether you think the metronome marking is more important or the tempo word. Both are viable options, but give different results. Here is a performance conducted by Paavo Järvi of the Symphony No. 9 that sticks pretty closely to the metronome markings. The third movement starts at the 28'00 mark:
I find this an excellent performance, by the way. I really enjoy the rhythmic 'groove' in the faster movements, especially the scherzo. But the adagio does sound a bit, ah, 'jaunty', does it not? And in point of fact, there is virtually no tempo contrast between the B flat opening section and the Andante section in D major. This, to me, is a serious interpretive problem. But you pays your money and you takes your choice. All interpretations are questions of choices. I think that Järvi has an interpretation that works--in some ways more effectively than Barenboim's, but I also think that Barenboim has an interpretation that works--in some ways more effectively than Järvi's.
I often talk about ideology and the unfortunate effects it can have on aesthetics. If I were to make my own choices in this symphony I think I would tend to go along with Järvi for the first and second movements, but with Barenboim for the third. I think the contrast between the Adagio and the Andante is more important than whatever number Beethoven wrote down for the metronome marking. In other words, I think interpretive choices should be based more on musical than ideological considerations. Lurking behind a lot of "movements" in the arts are ideologies. The rule that "Beethoven's metronome markings must always be followed rigidly" is an ideology, not an interpretation.
And by the way, Beethoven left no metronome markings for his late quartets so there the performer is entirely on their own...