Berg began studying composition under Schoenberg in 1904, composing over 100 Lieder as student exercises. The Piano Sonata, composed between 1907 and 1908, was initially conceived as a multi-movement sonata, but it became a single-movement sonata following the advice of his teacher, Schoenberg.

This single-movement sonata is outwardly composed in sonata form, as typically found in the first movement of a classical sonata. That is, it features multiple themes of differing character, with a repeated exposition followed by development and recapitulation of the themes. In this sense, it differs from single-movement sonatas like Liszt's Piano Sonata, which compress multiple movements into one.

However, the musical content turns away from classical sonata conventions. Although the key of B minor is established by two largely conventional sharps and occasional cadential progressions, the process of modulation to related keys, which served to clearly delineate sections in traditional sonatas, does not function in this work.

From the outset, the thematic material is highly restricted, and the piece progresses by combining these limited elements, giving the impression, in an extreme sense, that the entire work is in a constant state of development.

In the opening principal theme, a major seventh interval is first presented, and its inversion, a minor second, forms the bass line and inner voices. Subsequently, a descending major third motif of a second appears in the melodic line, forming an augmented triad. Following a B minor cadential figure, the music immediately progresses by combining these two types of interval relationships, and in measure 7, a whole-tone scale emerges in connection with the augmented triad.

Thus, from the very beginning, the piece is constructed through highly intricate motivic interval manipulation.

After a characteristic transition featuring an eighth-note triplet motif, the subordinate theme, appearing from measure 29, is initially impressed with A major by a preceding E dominant seventh chord (with the fifth raised by a semitone) and a sustained A. However, minor second intervals and whole-tone scales appear throughout, and despite their differing character, connections to the principal theme can be found everywhere.

A sixteenth-note sextuplet motif, related to the eighth-note triplet motif from the preceding transition, and a melody derived from it combine with the principal theme's motif to form the coda (from measure 49).

The development section (from measure 56) begins with the principal theme's motif, but rather than motivic development, it heightens tension by combining various rhythmic elements that appeared in the exposition, leading to a catastrophe in measure 91. Subsequently, the motif of the subordinate theme leads to the recapitulation of the themes.

The return of the principal theme (from measure 111) marks the recapitulation, and the subordinate theme appears over a B pedal point (measure 137). When the coda motif, derived from the sixteenth-note sextuplet transition motif, appears as in the exposition (from measure 167), this motif appears in inversion in the bass voice (from measure 171), and the piece concludes in B minor while the principal theme's motif is repeated.

This compositional technique of weaving other motifs and themes from the motif of a single theme can be seen as closely related to what Schoenberg termed "developing variation." Schoenberg used this term in reference to Brahms's works, and it is possible that what Berg learned under Schoenberg was precisely this technique of motivic manipulation.