An impromptu (, French: [ppty], loosely meaning "offhand") is a free-form musical composition with the character of an ex tempore improvisation as if prompted by the spirit of the moment, usually for a solo instrument, such as piano. According to Allgemeine musikalische Zeitung, Johann Baptist Cramer began publishing piano pieces under the (sub-)title of "impromptu." (AMZ, Mar. No II, 1815, col. 6), which seems to be the first recorded use of the term impromptu in this sense.
Since the very concept of unpremeditated, spur-of-the-moment inspiration without studied care is at the heart of Romantic artistic theory, it did not take long before the first generation of Romantic composers took up the idea. Others were:
The impromptu genre remained popular all throughout the 19th century and were prominent throughout the romantic era.
In the 20th century, there are also several examples of composers naming their compositions "Impromptu", such as: