Score, including early version and revised version.

These Impromptus are arrangements of the impromptus for piano from op. 5. The exact date for arranging the piano impromptus for string orchestra is presently not known, but it took place approximately in late 1893 or early 1894. Probably Sibelius first arranged only Impromptu no. 5 for string orchestra.

No set of parts or information on any performances of no. 5 during Sibelius’s lifetime survive. Perhaps Sibelius decided to combine Impromptus nos. 5 and 6 into an ABA form before performing no. 5. The combination, presumably the early version, was then premiered on 17 February 1894. At some point Sibelius made changes on the score and eventually faircopied the revision. Of this revised version of no. 5–6, surviving as copyists’ copies, only one autograph page survives as a photograph.

The main differences between the versions of no. 5–6 lie in the form, more precisely, in the repetitions. Both have the form of ABA and in the early version, the latter A corresponds to the first completely, whereas in the revised version, the repetition is shortened.

Additionally, the revised version includes a repetition of the latter part of the B section.