The stylistic departure that began with Beethoven's piano sonata No. 12 continued with the following two sonatas of Op. 27, which the composer completed in 1801 and published with the description “quasi una fantasia.” With Sonata No. 13 in E flat major, Beethoven again chose to implement unconventional forms, beginning with the opening movement: an Andante–Allegro–Andante structure that sugges...
