Composed between 1803 and 1804.
And now we’ve reached the incandescent marvel that is the Waldstein. It’s one of Beethoven’s most expansive and uplifting works, but its instant likability sometimes obscures that fact that it’s a deeply restless and innovative work, structurally and texturally extraordinary in ways that sound natural only because the sonata is so well-put together.
Take the opening of the first move. What kind of sound is this? It's tense without being dramatic, ambiguous without being vague, moving and shapeless, and auditory without any sense of harmony, even though it's just a C major chord in the root position, of all things. There is also the tonal uneasiness of this work: right after the C major chord we get a secondary dominant, followed almost immediately by an unprepared shift towards B flat major, this is one of those moments that is they reproduce as a funny gesture or as something more mysterious. The second group of themes (which has a striking link to the first theme in the form of a 5-note descending motif) is in E major, rather than the more normal G Major | F major | The minor. And the recap is surprisingly fun; there are little scripts of new material and the second thematic group goes into the more frivolous A major, another "wrong" tone. There's more, like this little infinitely flexible modulation idea, but that will be highlighted below.
The second movement, an expanded introduction to the rondo, is one of Beethoven's slow and harmonically deceptive pit movements, and the rondo itself is a flash of wonder. There's theme A, floating in a haze of fuzzy harmonies; a B theme that he builds for the second time in a huge orchestral spiel; a transitional motif, based on theme A, joyful, sad and noble at the same time; and an extended coda that is as evolutionary as it is brilliant. The mere fact that the latest movement carries so much weight was quite novel for the time. Beethoven gradually shifted the heavy lifting from first to last movement in his 32 sonatas.