30 or 60 seconds long, an ad-lib is an announcer-read promotion of an advertiser's product from bullet points supplied by a client.

remark made spontaneously without prior preparation; "his ad-libs got him in trouble with the politicians"

perform without preparation; "he extemporized a speech at the wedding"

said or done without having been planned or written in advance; "he made a few ad-lib remarks"

with little or no preparation or forethought; "his ad-lib comments showed poor judgment"; "an extemporaneous piano recital"; "an extemporary lecture"; "an extempore skit"; "an impromptu speech"; "offhand excuses"; "trying to sound offhanded and reassuring"; "an off-the-cuff toast"; "a few unrehearsed comments"

Unrehearsed, spontaneous act of speaking, performing, or otherwise improvising on-camera activity without preparation.

To improvise lines or speeches that are not part of the script.

Speech or action that has not been scripted or specially rehearsed

to make up a joke within a scripted show.