improvise

v. (-sing) (also absol.) 1 compose or perform (music, verse, etc.) Extempore. 2 provide or construct from materials not intended for the purpose.  improvisation n. Improvisational adj. Improvisatory adj. [latin improvisus unforeseen]

v. t. To compose, recite, or sing extemporaneously, especially in verse; to extemporize; also, to play upon an instrument, or to act, extemporaneously.