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 n...