‘Interstitial’ simply means something existing or placed between two other things. Therefore, an interstitial reaction is a reaction you perform between your phrase groupings of dialogue.
The purpose of an interstitial reaction is to resonate one of the specific groups in the audience. Since there are groups of sad, anxious, angry and happy people in the audience, we will resonate each group one at a time. I’ve seen Marlon Brando string 3 or 4 different interstitials together thus telling a story about his character. Try it.
http://www.amazon.com/s/ref=nb_sb_noss_2?url=search-alias%3Daps&field-keywords=action%2Freaction+stephen+mitchell
