Franz Schubert's Impromptus are a series of eight pieces for solo piano composed in 1827. They were published in two sets of four impromptus each: the first two pieces in the first set were published in the composer's lifetime as Op. 90; the second set was published posthumously as Op. 142 in 1839 (with a dedication added by the publisher to Franz Liszt). The third and fourth pieces in the first set were published in 1857 (although the third piece was printed by the publisher in G major, instead of G♭ as Schubert had written it, and remained available only in this key for many years). The two sets are now catalogued as D. 899 and D. 935 respectively. They are considered to be among the most important examples of this popular early 19th-century genre.

Three other unnamed piano compositions (D. 946), written in May 1828, a few months before the composer's death, are known as both "Impromptus" and Klavierstücke ("piano pieces").

The Impromptus are often considered companion pieces to the Six moments musicaux, and they are often recorded and published together.

It has been said that Schubert was deeply influenced in writing these pieces by the Impromptus, Op. 7 (1822) of Jan Václav Voříšek and by the music of Voříšek's teacher Václav Tomášek.

The second set was also composed in 1827, but the pieces were not published until 1839.

Impromptus, Op. 142, D. 935

Schubert was a prolific composer, and despite his personal struggles, he produced a plethora of works in the late 1820s. The Impromptus were composed during a particularly creative period in 1827, which included the Piano Trio No. 1, Piano Trio No. 2, the Impromptus, Op. 90, the Fantasy for violin and piano and some 30 other works.

The Impromptus were part of the broader Romantic trend of composing short, self-contained piano pieces, a genre popularized in the 1820s. Other composers such as Johann Baptist Cramer, Carl Czerny, Heinrich Marschner, Ignaz Moscheles and Franz Lisztalso wrote Impromptus published around this time, though Schubert's clearly structured Impromptus largely do not conform to the improvisational traits implied by the literary term "impromptu".

The autograph of the Impromptus, Op. 142 is dated to December 1827, and they were first mentioned in a letter from Schubert to the publisher Schott in February 1828. There is no documentary record of the first performance, though it is likely that they were first performed at a house concert in Vienna in early 1828 by Carl Maria von Bocklet, who had also premiered the Piano Trio No. 2.

Schubert had difficulty getting the Impromptus, Op. 142 published. His publisher Tobias Haslinger had already published two other Impromptus (Nos. 1 and 2 from Op. 90) and was not interested in the new set. Similarly, they were rejected in October 1828 by Schott as being too difficult and therefore "unmarketable in France". The work was published posthumously in 1839 by Anton Diabelli in Vienna.

The first Impromptu in F minor follows the form of a sonata exposition. The second Impromptu in A-flat major is written in the standard minuet form. The third Impromptu in B-flat major is a theme with variations. Finally, the fourth Impromptu in F minor is highly virtuosic and the most technically demanding of the set. Due to their structural and thematic links, some envisioned the four Impromptus as parts of a multi-movement sonata, a conjecture which is subject of debate among musicologists and scholars.

Read more: https://en.wikipedia.org/wiki/Impromptus_(Schubert)

https://en.wikipedia.org/wiki/Impromptus,_Op._142_(Schubert)