What does "building up to" mean?

One of my favorite examples of this is in "Silence Of The Lambs", in the scene where Clarice is first introduced to Doctor Hannibal Lecter.

It begins with very subtle but terrifically effective audio work; low thrumming sound beds that grow over time out of nothing, as the moment of meeting approaches, a steady, growing pressure in the brain. Visually, from a story-telling aspect, the preparations, the form-filling of the safety waiver, the "mandatory" showing of newspaper clippings, autopsy reports, the pictures of staffers who let their guard down, the choice of lens and lighting and camera angle, the increasing tempo of the cutting, all sort of force you into a tighter and tighter squeeze, like a cattle chute, past the other inmates of the wing, each of them in turn more horrible.... and then you get to...

... a nice-looking old guy behind a plastic wall? And for a moment, you're confused, becasue he doesn't look all that bad....




Certainly, Demme could have just cut directly to a scene where Clarice walks up to Lecter's cage and starts a conversation. But there's no tension build there.
And no exposition.


Another famous example I like is the old TV show: "Kolchack: The Night Stalker" Starring Darren McGavin. Every week, there's a monster or demon to confront, but in the beginning, you barely see anything of it at all. Over the course of the hour, you get a few more glimpses, but only glimpses, a few frames to a second or tow, until the big finish, where the THING comes out in full view for the final combat. Much more effective than showing the monster in full in the first reel, as you enlist the audience's imaginatino to fill in the missing pieces.


Sme typical techniques of editing used to "build up" to something include parellel action, where the POV cuts back and forth between, say, the guy trying to crack the safe, and the owner of the safe, returning from an outing, early.

Or tempo, like in "Rear Window", when the bad guy is getting closer and closer to the wheelchair-bound photographer, only his progress is seen in the strobe flashes of his camera going off, as he gets closer... closer...closer....

Thanks to you and Mark for clear, succinct enlightening explanations.