found: Work cat.: Memories lost, 2014:container insert (Impromptu, op. 9 / Yu Julian)
found: Merriam-Webster dictionary online, Sept. 8, 2017(impromptu noun 1 : something that is impromptu 2 : a musical composition suggesting improvisation)
found: Wiktionary, Sept. 8, 2017(impromptu (plural impromptus) 1. (music) a short musical composition for an informal occasion often with the character of improvisation and usually to be played solo. 2. any composition, musical or otherwise, that is created on the spot without preparation.)
found: Oxford dictionaries website, Sept. 8, 2017(impromptu noun A short piece of instrumental music, especially a solo, that is reminiscent of an improvisation)
found: Grove music online, Sept. 8, 2017(Impromptu: A composition for solo instrument, usually the piano, the nature of which may occasionally suggest improvisation, though the name probably derives from the casual way in which the inspiration for such a piece came to the composer; the swift figuration and the thematic material of each of Chopin's four celebrated impromptus are so akin as to suggest that he intended them to form a coherent group--each one after the first to be, so to speak, improvised from, or casually derived from, the material of the previous one; examples of impromptus can be found in the work of Sterndale Bennett, Skryabin, Fauré, Lennox Berkeley and Roberto Gerhard)
found: The Oxford companion to music, via Oxford music online, Sept. 8, 2017(impromptu: An instrumental composition, not necessarily (despite its name) of an improvisatory character. 'Impromptu' was used as a title for short piano pieces in the 19th century, the earliest known examples being by the Czech composer Vořišek (1822). The most famous are those of Schubert (he adopted the name only after his publisher, Haslinger, had called the first four of his 1827 set 'impromptus') and Chopin (opp. 29, 36, 51, and 56--the last better known as the 'Fantaisie Impromptu', 'Fantaisie' having been added to the title by Chopin's editor))
found: The Oxford dictionary of music, via Oxford music online, Sept. 8, 2017(Impromptu: Literally 'improvised' or 'on the spur of the moment', but in 19th cent., name given to short piece of instr. mus., often in song‐like form, e.g. those by Schubert, Chopin, and Schumann)
