(1781) 3 " " A minor 1774 Hamburg.
" " " D minor (Bülow No. 5) 1766 Potsdam.
" " " F minor (Bülow No. 1) 1763 Berlin.
(1783) 4 " " G 1781 Hamburg.
" " " E minor 1765 Berlin.
(1785) 5 " " E minor 1784 Hamburg.
" " " B flat 1784 Hamburg.
(1787) 6 " " D 1785 Hamburg.
" " " E minor 1785 Hamburg.

Without copious musical examples, an analysis of these eighteen
sonatas would prove heavy reading. It will, therefore, be easier for
the writer, and certainly pleasanter for his readers, to give a
somewhat "freye Fantasia" description of them, laying emphasis
naturally on points connected with the special purpose in view.[70]

In the matter of tonality there are some curiosities. When Beethoven's
1st Symphony appeared, the opening bars of the introduction became
stumbling-stones to the pedagogues of that day. The work was, without
doubt, in the key of C major; yet, instead of opening with the tonic
chord of that key, the composer led up to it through the keys of the
subdominant, relative minor, and dominant. No wonder that such a
proceeding surprised conventional minds, and that the critics warned
Beethoven of the danger of "going his own way." But his predecessor,
Emanuel Bach, had also strayed from the pedagogic path, a narrow one,
yet, in the end, leading to destruction. In the first book (1779), the
5th Sonata (as shown by the whole of the movement, with exception of
the two opening bars) is in the key of F major, yet the first bar is
in C minor (minor key of the dominant) and the second, in D minor
(relative minor of the principal key).