Up until now I have been teaching you about the three-act structure and I'm about to blow it all out of the water by talking about the often-misunderstood 4th act.
Let me show you how to include a 4th act when you are writing trailer music.
What is the 4th Act?
In my courses, I often refer to the 4th Act as the 3rd Act's outro. It is essentially a last section of music that briefly hammers home the root note of the track. Or it gives us one final frenetic push just before, or on the final Title card.
What goes into the Music of Act 4?
Treat the music in the fourth act as an epic drum fill layered with risers, the root note of the chord and a subtle whiff of character.
That character can take the form of a signature sound or a tiny part of the track's melody as a nod to what has gone before.
The Final Push
As you can see in this trailer for Jurassic World Dominion, the 4th act comes as the last frenetic push: drums, chromatic movements, risers and choirs all add that last musical slap in the face before the title card.
Where the Sh*t Hits the Fan
These Dungeons & Dragons trailers show another use for the 4th act; when it all falls apart. This is used to bring the action into the title card.
Crank it Up to 11
Act 4 is your chance to crank your music up to 11!
Don't worry about it sounding too "crazy" or getting too "busy". This is the point in the trailer when the editor makes you think that everyone dies, or at least is in dire peril. The music has to reflect that.
I like to use a tempo change to give it that extra lift, but really all it needs is driving percussion, risers, and hammering home the root note of the track.
This John wick trailer is an excellent example of that relentless driving percussion layered with orchestral hits.
How Long Should Act 4 be?
Act 4 is really only an extended ending, or drum fill on the end of the previous 3 acts so it only needs to be 5-15 seconds long. It needs to be punchy so the shorter the better.