I've written before about some of the great articles in the Beethoven Compendium and one other which I really liked was written by William Drabkin titled "Musical form: Innovations". Here Drabkin tries to distill in just a few pages some highlights of Beethoven's innovations regarding symphonic form. I'll paraphrase a few highlights here:
1 - Expanded conception of how big (or small) a movement could be.
By increasing the size of the exposition in the 1st movement of a symphony or chamber work, B. also had to increase the remaining parts proportionately. He did this sometimes by writing a kind of "double development" - that is 2 developments connected by a transition or a false recapitulation. This happens in String Quartet Op. 59 No.1, Symphony 3 (Eroica), and several piano sonatas (including the Waldstein, Appassionata and Hammerklavier). B. also tried miniaturization of some movements, some of which can also be considered as musical ligature (see #3 below) (ex. late string quartets, Piano Sonata Op.78, String Quartet Op. 95, 8th Symphony).
2 - Created greater continuity between adjacent movements.
B. worked to unite movements so that they would fit together to form a unified statement. One technique he used was parcelling out similar interval relationships between the first and last movements (ex. a major third interval is used in the first and last movements of Piano Trios Op.1.3 and Op.1.1). A minor third interval is integral to the 1st, 3rd and final movements of String Quartet Op.130 (the Grosse Fuge being the final movement).
He also wrote connected movements which would not otherwise work alone (Piano Sonata Op.27 No. 1 and 2 (Moonlight), as well as sometimes cutting out a final cadence or landing on an unstable chord to produce a feeling of connectivity (Appassionata sonata, also Violin Sonata Op. 96, Piano Trio Op 97 "Archduke", Cello Sonata Op.102 No. 2). His Violin Concerto Op. 61 and the 5th Piano Concerto both have motivic material connecting the 2nd and 3rd movements without pausing.
Sometimes slow movements were reduced so that they seemed to fit the role of introductions to the final movement rather than "adagio" movements in their own right. (Waldstein Sonata, Cello Sonata Op.69, Piano Sonata Op.101).
Many times B. worked at setting up the finale as the emotional center instead of 1st movement (as was more typical of Haydn and Mozart). In the 5th Symphony, the 3rd movement is "relieved" by the victorious modulation to C Major in the finale. The 9th Symphony and String Quartet Op. 130 both have their finales as the "heavyweight" portions of the larger form (the Grosse Fuge in the case of Op. 130).
3 - Utilized musical chunks to create larger compositions.
As mentioned above, String Quartet Op.130 has 6 movements which create a kind of harmonic "arc" from the 1st movement to the last. String Quartet Op. 131 has 7 movements, of which parts 2, 3 and 6 are very short and can be seen as "chunks" connecting larger statements. Piano Sonata Op. 110 also has a final movement in which there are discrete sections actually within the same movement (introduction, arioso dolente, fugue, recall of arioso dolente...).
Drabkin ends with this:
"By a variety of techniques Beethoven breaks down the concept of 'movement' in many of his works, and makes the work as a whole the artistic unit of measurement...This is a quality one senses in much of the best of Beethoven's mature works, even those which are morphologically (structurally) more conventional. Works like the Eroica, 5th and Pastoral symphonies, and the Hammerklavier and late E major piano sonatas, to name just a few of the most obvious ones, are stories told in music."
OK, off to the Daily Beethoven Index to look up all these works to hear this in action...
(hmmm...maybe tomorrow will be a bit lighter on the 'academics'...)