Laughter induced by a joke on a TV series such as Scrubs, which is followed by a snippet of slap bass and a drumroll. This brief section of jazz can also induce the laughter, as it's primary function is to inform the show's audience that something funny just happened.
Mr A: "Hey Dr B, I was watching some Scrubs last night and found myself laughing more at the jazz music than at the slapstick humour before it..."
Dr B: "Ah yes, I diagnose you as having a Jazz Laugh. It'll stop when the serious bit at the end of the show kicks in."