The increasing range of Beethoven’s performance indications paralleled the growing depth of expression in his music. While his predecessors had been content with four basic tempos—adagio, andante, allegro, and presto—he began to add qualifiers, indications of gradual tempo change, and descriptive words and phrases in German.
Still unsatisfied, he began to rely on metronome markings, although he stressed that they only provide a point of departure for a performance in which “feeling also has its beat, which cannot wholly be conveyed by a number”.
He started to favor graphic treatments of crescendo and diminuendo, ensuring dynamic shapes that would not necessarily be intuited by the performer. He used sforzando in structural as well as expressive ways, and expanded volume markings beyond the range from pp to ff.
His pedaling indications usually reinforce harmonic contexts, though sometimes they cause harmonic areas to overlap; this might explain why some of Beethoven’s contemporaries complained that his pedaling resulted in a confused sound. His articulation markings often reinforce motivic structure and development.
All of these performance indications are most fully understood in the context of the particular instrument he was using at the time.
This according to “Interpreting Beethoven’s markings: A preliminary survey of the piano sonatas” by Tallis Barker (The music review LV/3 [August 1994] pp. 169–182). Below, Sviatoslav Richter demonstrates his approach to Beethoven’s performance indications.