improvisation

noun4

1. •
   The act or art of composing and making music, poetry, and the like, extemporaneously

   • He played a quick improvisation on the keyboard.
2. •
   Musical technique, characteristic of blues music.
3. •
   The act of improvising, acting or going about something without planning ahead

   • The Ivorian is a player with such a liking for improvisation it does not usually look like he has any more idea than anyone else what he is going to do next, so it was an interesting choice. — 2012
4. •
   That which is improvised; an impromptu.