improvisation:
 The act or state of being improvised, as in 1) a] A course pursued  with no previously conceived policy, plan, or consideration in mind,  or b] The extemporaneous quality of such a course — spur of  the moment; 2) a] extemporaneous creativity b] the extemporaneousness of said creativity; 3) Something improvised, or designed to appear improvised [IMPROVISE — to devise from whatever material is available.] Compare IMPROMPTU.