Pianofall but in Unreal Engine...
Warning
Chaos can crash on larger midis, I'm trying to fix this.
To merge the frames you need to execute this command in the directory where the frames are located (Frame000001.png, Frame000002.png, Frame000003.png, etc...):
ffmpeg -i audio.mp3 -framerate 60 -i Frame%06d.png output.mp4