The trailer for "The Caveman's Valentine" is one of my favorites; it's a fantastic example of the power of good music, and editing.
I saw this film when it came out, and was thoroughly disappointed. Though when you take a good look at this trailer, what does it really tell you about the plot? What was the approach of the trailer editor, and why did it work so well? (on me at least; it bombed at the box office)
The trailer starts off with shots of piano keys, and the flapping of bird wings. As the song begins we see very quick flashes of a body and "HELP ME" written in red. This is a good lesson in shot readability. Of the shots, the body and "HELP ME" are what I process easiest. This is because people can read very quickly, and human bodies and faces are very recognizable. There are also closeups on body parts, but they're more difficult to identify.
Even in this very short intro, the music pulled me in, and the quick images intrigued me. Then seeing Samuel L. Jackson talking to the camera sealed the deal. Everyone loves when Samuel L. Jackson yells, right?
As soon as the beautiful music kicks in, I'm fully locked in. When I see Samuel L. Jackson looking like he's homeless intercut him nicely dressed up playing piano, I can't help but wonder: What is the story behind this character? Anthony Michael Hall then literally asks a question, and gives a bit more context that he went to Julliard.
Before that, some people on the street call him a caveman, and that's reiterated by his daughter talking to him about living in a cave.
A title card sequence starts, letting us know that it's based off of an acclaimed novel. We get a bunch of abstract imagery, and a line about moth seraphs living in Samuel L. Jackson's head. This sequence means virtually nothing without context, but the music is so pretty, and the visuals are interesting, do we even care? I certainly didn't. I don't think I even understood the line "moth seraphs" until I saw the film.
The sequence is sandwiched by "From the Director of 'Eve's Bayou'" I've never seen "Eve's Bayou" but a title card calling out a director tells the audience they're noteworthy. Sidenote: I'm always suspicious when the title card "From the creators of..." or "From the producers of..." is used in trailers, because it sounds like they're reaching for anything to make the film seem more significant.
Now that we have some context for the character, there's just a bit of plot introduced. Outside his cave is a body that's believed to be someone who froze to death, but for some reason Samuel L. Jackson thinks they were murdered.
How does he know that? There's more abstract imagery we have no context for, but music is very pretty so I'm still on board.
A white guy asking Samuel L. Jackson who he is, then Samuel L. Jackson yells at the Chrysler Building. He yells real good, so of course it's engaging. Then there's some action with a car chasing him down, and a masked person in a gun. This is kind of a leap from the previous section of the trailer, but it stands to reason if he knows something he shouldn't, people might want to cover it up.
The music closes out as the trailer teases some sort of confrontation between Samuel L. Jackson, and presumably the killer. Then we get the title, "The Caveman's Valentine" which is a very intriguing title.
The film bombed at the box office, but I still watch the trailer to this day. At only 1 min 44 seconds it's pretty short, more teaser length than full trailer, but having seen the film, this is as good a trailer as I think was possible. As I recall, nothing in the plot was terribly interesting, and at times seemed to make no sense at all.
The trailer leans very hard on the music, Samuel L. Jackson and the character premise. The character is by far the most unique part of the story, so it makes sense to highlight it over the plot. The music and editing are what really took it to the next level. I'm never going to stop saying that the vast majority of the time, music is the most important part of the trailer.
If you imagine this exact same trailer, but with some sort of rock music, it wouldn't be nearly as interesting. The fact that the music ties into the character makes it all the better. I think the contrasts between the music, murder story, and Samuel L. Jackson as a musician living in a cave are what got me to buy a ticket.
The fact that I didn't enjoy the film at all could make the argument that you should be suspicious of fancy editing in trailers. That's not always the case, but I definitely raise my eyebrows when scenes aren't allowed to play out in a trailer.
This is why I'm cognizant of making my editing too stylized, because I don't want the audience to consciously or subconsciously think that I'm hiding something (also because stylized editing is hard :P).
So what's the lesson here? Find great music for your trailer, focus on what is unique about the story, and when there's something that is too weak to carry the trailer, show less of it. Showing less in a trailer can benefit you, because often the audience will imagine what the rest of the film will be like, and if that excites them, they're likely to go see it.
Even though a savvy trailer audience will always be skeptical, I think that when we see bits and pieces that we like, we can't but want to believe the omitted portions must also be pretty good too! This is why it's so frustrating to watch a trailer that seems to show everything from the film, because don't get to imagine any of the potential. When the audience thinks they've seen everything, there's no nagging feeling in their head that says to them: "You should find out more about this."