When in 1807, at the age of twenty, Weber arrived in Stuttgart to take up a post as secretary to Duke Ludwig of Württemberg, he brought with him the Adagio of his Piano Quartet in B flat major, J76. It was already his custom to write his slow movements first, following them with a finale; only later would a first movement be added, or sometimes never written at all so that there are works which remain simply ‘Adagio and Rondo’. This reflects his lack of sympathy for the classical discipline of sonata form in an opening movement, and his greater attraction both to Romantic explorations into new areas of harmony and colour, and to increased instrumental virtuosity. Most originally, the Piano Quartet’s Adagio is less concerned with themes or melodies than with such unusual gestures as the opening chords on the strings answered by a piano flourish, or the effect of throbbing piano chords against impassioned, wide-ranging string phrases, or, in the wild central section, a chordal progression with forceful violin leaps against a murmurous running figure on his beloved viola. The balance between piano and strings in chamber music is notoriously tricky; with his devotion to novel textures and his acute ear, the inexperienced Weber has found his way to some fascinating solutions.
The Allegro which he added to open the Piano Quartet is also unusual. Though it is cast in sonata form, Weber abandons convention as soon as he interestingly can. This is most evident at the start of the development. For classical composers, this was generally the section in which the most inventive working out of themes would take place. Weber is less attracted to this than to finding new themes in unexpected ways. None is more beautiful than the singing viola melody to which the other strings and the piano defer. His recapitulation is more regular, and ends with a graceful gesture to the opening of the whole movement. Even in the Menuetto, which follows the Adagio, there are metrical and harmonic surprises, as Weber answers his soft, uneven opening phrases violently and in an unexpected key (A flat in the key of G minor). He goes even further in the trio section, in the middle of which a forceful return of the opening rhythm drives the music into another startlingly remote key, G flat. His finale is a pianistic tour de force, serving notice that here, barely out of his teens, was one of the pioneering artists of Romantic virtuosity. The Quartet was completed on 25 September 1809.
from notes by John Warrack © 2005