“Beethoven was a classical musician. He used the same grammar rules that you can find in Haydn’s works,” (Jaime Kardontchik, “Modulation in Beethoven’s Sonatas“). “So why does his keyboard music sound so vastly different from Haydn’s or Mozart’s music? For one thing, he was a son of the French Revolution with its Republican ideas of Liberty, Fraternity and Equality. He was an eighteen year old teenager when in 1789 the French Revolution shattered the pillars of the old monarchical world and he enthusiastically embraced these new ideas.
But what made in the end his keyboard music so distinctive is that papa Haydn and the younger Mozart grew up with and perfected the technique of playing and composing for the 4.5-octave harpsichord … Mozart died prematurely in 1791. The young Beethoven grew up together with this new and different keyboard instrument, the forte-piano. He extracted from the forte-piano every new sound possible as the piano makers were improving the instrument and expanding its range up to the present 7.5-octave piano as it is known today. Beethoven loved its sound, however imperfect the instrument was in his time; he understood the almost unlimited possibilities it opened for the expression of new musical ideas, took the risk, and bet on it. And two hundred years later, we are happy he did so. But historical circumstances and technical developments are clearly not enough to explain the individual and his contribution: he was simply Beethoven.”
After a start in C minor, a modulation into the relative major key (Eb) is in effect between 0:33 – 1:11). The 1798 sonata’s sprightly prestissimo movement continues to transition between the two relative keys throughout, passing through other keys (C major included) in the process.