Tenakoe Ollie

One of the first jobs I ever had in a cutting room was to drop the appropriate 2, 4, 6, boundary or out of the ground prerecorded applause into a track against the 2, 4 runs etc marked on the cut film by the editor. This was taken to a recording studio and commentary added. This was before videotape. It was an advance on the really early ABC cricket broadcasts where the commentator listened to the badly transmitted commentary from England and repeated it, hitting the desk with a pencil to approximate ball and bat.

Re loop groups: it was not uncommon for the dialogue editor to be left to direct walla. In NZ the group was usually assembled from office staff and crew, but it was invaluable to have at least one experienced actor to drag any performance out of the non-actors. My experience with US extras recordings is that lower ranked actors specialise in this job; a loop group captain is contracted, given a profile of male/female/ages and he or she gets the group together and virtually directs the session.