Sibelius extensively revised the Impromptu in the spring of 1910, reducing the instrumentation and altering both the beginning and ending of the piece, the former of which now incorporated a second Rydberg poem, Bacchospräster (The Priests of Bacchus).[2][5] This version of the Impromptu received its premiere in Helsinki on 29 March 1912, with Sibelius conducting the Philharmonic Society;[6] "Nuori Laulu" and the Arbetets vänner [sv] female choir sang the choral part.[2]
Newspaper advertisement (in Finnish) from Uusi Suometar for the premiere of Jean Sibelius's Impromptu
The Estonian conductor Eri Klas and the Finnish National Opera Orchestra made the world premiere studio recording of the Impromptu in 1990 for Ondine.[2] The table below lists this and other commercially available recordings:
^Refers to the year in which the performers recorded the work; this may not be the same as the year in which the recording was first released to the general public.
Barnett, Andrew (2007). Sibelius. New Haven: Yale University Press. ISBN978-0-300-11159-0.
Dahlström, Fabian[in Swedish] (2003). Jean Sibelius: Thematisch-bibliographisches Verzeichnis seiner Werke [Jean Sibelius: A Thematic Bibliographic Index of His Works] (in German). Wiesbaden: Breitkopf & Härtel. ISBN3-7651-0333-0.