There are many creative editing techniques you can apply to your videos, from on-screen text animation to transitions, masking, and more — but what if you could make objects or text react to sound automatically? With the help of After Effects expressions you can do this in less than five minutes!
Step 1: Select Your Sound and Background
In the background, behind the text, I like to have some type of visual playing, whether it’s a video clip or some type of lens flare. For this type of effect, I particularly like to use aerial shots, so I chose this New York Helicopter shot.
Step 2: Create Your Text
After you create a composition with your clip, choose a font that matches the style of your video and use the type tool create the text you want to animate to the music.
Optional: You can apply a gaussian blur to your image so that the background is more out of focus compared to the text, bringing in more focus on your text. You can also apply a drop shadow to the text to give it more of an extra pop, as well.
Step 3: Convert Your Audio to Keyframes
Drag your audio clip into your composition, right-click on the clip, and select “Keyframe Assistant” and “Convert Audio to Keyframes.” This creates an audio amplitude layer which sets a keyframe at every beat of the music. You can delete the left and right channels if the music track is stereo, which this one is.
To better see the keyframes, you can click on the graph editor, which will provide a visual of how it mapped the music track into audio and keyframed the beats.
Step 4: Pick Whip Text Scale to Audio Amplitude Slider
The next step is to choose the parameter you want to animate to the music. The most common path is to choose the text’s scale, so that the scale will grow smaller or bigger to the beat of the music. First, while holding the alt/option key, select the toggle animation stopwatch next to “Scale” to activate expressions. Then take the pick whip and drop it on the slider control from the audio amplitude layer. Now your text animates to the music, but you will see it reduced in size.
To change the size of the text, from the Expression field next to Scale, add “+[75,75]” or any value between 0-100 until you get the scale right. So, depending on what size you want to make the text, you could instead try +[50,50] or +[100,100].
Note: You can animate any effect to the beat of the music. So if you apply a glow effect to your text layer, you can pick whip any parameter from that effect and animate it.
Step 5: Smoothing and Customizing the Animation
Right now, the text is animating to every beat in the track, and visually this can look a bit jolty. To make the animation smoother and to limit the amount of beats, go back to the graph video of the audio amplitude. Just as we did with the scale of the text, activate Expressions on the slider control by hitting the alt/option key and selecting the stopwatch next to the slider.
Then, in the Expression field type out the following:
Ease is an expression used to “smooth” out the animation, and the 0,0,0,0 is where you’re going to place your own custom value range depending on what audio range you want and how much you want the text to scale.
The first two numbers refer to the audio range units, so if you only want to the text to animate to beats between 45 and 60 units, you are going to put ease(value,45,60,0,0)
The next two numbers refer to the scale at which you want the text to animate — it can between 0 and 100. If you only want it to scale up to 50%, then you would type ease(value,45,60,0,50).
Now the animation is smoother and only animates to the audio units between 45 and 60 and at a scale from 0 to 50.
That’s how to make text auto-react to your music — and remember, the same method can be applied to graphic layers! So for example, if you have a logo and you want it to react to the sound effect, you can do that in the same way.