played by ear

offhand spontaneous unscripted

ad-lib fake

dashed off extemporaneous extempore extemporized faked improv improviso off the cuff shot from the hip spur-of-the-moment thrown off tossed off unpremeditated unprepared unstudied vamped whipped up winged

deliberate planned

ad-lib extemporaneous improv improvised improviso offhand shot from the hip spontaneous spur-of-the-moment unpremeditated unprepared unrehearsed unscripted whipped up winged

unaware vulnerable

ad-lib caught off guard ill-considered impromptu improvised napping not prepared off the cuff off the top of one's head offhand spontaneous surprised taken off guard unexpected unplanned unready unrehearsed unschooled unskilled untrained winged