The opening of Beethoven’s Fourth Piano Concerto has no parallel in the repertoire. Concertos usually begin with a powerful orchestral introduction that exudes energy. In virtually all of the concertos of Mozart, Haydn and their contemporaries, the solo instrument only makes its entry after this first orchestral statement, by which time the orchestra has already stated the main material. In Beethoven’s G major concerto, the piano begins with an infinitely simple passage that presents in a hushed confession, the principal motif. It creates the effect of the composition unfolding from the personal confession of the soloist. The orchestra then answers the pianist’s phrase in a distant B major. Such tonal daring at the beginning of a work was not to be repeated again until Liszt’s A major concerto, written fifty years later. The first movement continues in more traditional vain: we hear a sonata form bridging section and subsidiary and closing themes. Since the concerto began with a tender, pianissimo theme, on this occasion the secondary theme is of a more "masculine" character.
The slow movement has encouraged some to interpret it in the light of the Orfeus myth. This association is not without foundation, since the piano solo pits extreme eloquence against strange unison replies from the orchestra, a depiction perhaps of the furies from another world being tamed by Orfeus’s song.
The finale follows on attacca from the slow movement. Its principal theme appears from afar. Initially it not only played softly, but approaches the basic tonality of G major from C major. Orfeus then has escaped from the world of the shades, and listening to Beethoven’s music, it appears he has extricated Euridice: one of the characteristic themes of the closing rondo proclaims triumph and happiness
The G major piano concerto was first performed in 1807 in Prince Lobkowitz’s palace. Beethoven was the soloist, although this was to be the last occasion when he undertook to perform a concerto in public.