Developing an Ear for Trailer Music
Developing an ear for good trailer music is an essential skill to both select music for trailers, and give direction to composers if there's no music to work from. Considering the diversity of things which trailers can be made for, it seems like there couldn't be any one set of criteria to look for. We're all familiar with the typical epic trailer music from Hollywood action films, but what about something for a more mellow tone? What about a stories which are: mysterious, comedic, family friendly, horrific, quirky, cute, sad, romantic, or any other possible tones?
Regardless of genre or tone, the three most important qualities for good trailer music are:
Build
Variety
Finality
A build is simply the feeling the song gets more and more intense as it progresses. It could start slow during the intro, then escalate in the middle, and reach a big epic climax at the end. The thing to remember is intensity is relative. Music doesn't have to end in an epic O Fortuna style chorus in order for it to be an exciting ending. As long as the music ends more intense than it started, you can create a sense of building towards an ending.
When I listen to possible candidates for a trailer music cue, I typically feel a sense of building when the cue seems faster or the instrumentation gets more layered. But this isn't always possible to find within one cue, which is why it's not uncommon to cut together a trailer with 2-3 pieces of music.
This is a fan trailer I made for The Dream Machine. This is 2-3 music cues put together in order to make the intensity increase. The climax isn't terribly high energy, but its contrast to the earlier music makes it feel bigger.
Variety seems like it would naturally create a sense of building to the end, and it certainly can, but it's entirely possible to have a music cue which has variety, but the energy stays at exactly the same level. This is especially true of video game music designed to loop indefinitely. It would be odd for the energy of the cue to feel like it's getting more intense only to have it reset and start building again. Cues with variety don't always have a sense of building, but generally cues which feel like they're building will feel like there's variety.
This music from Spelunky certainly has variety, but there isn't much of a build, and no sense of finality.
Finality is simply having an ending to the music cue which is satisfying in some way. Music designed to loop will end abruptly because it circles back to the beginning, but it's incredibly unsatisfying to watch a trailer where the music either simply cuts out without any climax, or the music continues playing and is faded out gradually.
If the in-game music satisfies the build and variety qualities, but has no ending, it's worth getting the composer to come up with something to "trailer-ize" the music so it has a satisfying ending.
For Neo Cab's E3 trailer, I initially worked with existing game music, and gave some guidelines for composer Joseph Burke who made this big exciting music cue.
These criteria are the most basic things to look or ask for in trailer music, everything else is just icing on the cake. If you have a variety of music cues to pick from which all fit the bill, the next thing to look for is highs and lows within each section. Music which has high moments and low moments within each section give you the opportunity to accentuate things along the way so that the intensity doesn't feel like a gradual rise.
This tutorial I made about how I mark up music cues should give you a sense of what an ideal situation looks like. A sense of build, variety, highs and lows, and moments where one section provides anticipation for the next.
I hope this helps you identify great music for your trailers, or give direction to a composer you're working for. For practice, try listening to a game or movie soundtrack, and picking out which songs you think would make good trailer music. If you have any further questions or difficulties, please ask!
