Annotating audio for music viz

I’m aware that work is being done on real-time beat analysis, and that’s great, especially for streaming input.
However, manually annotating key events in music achieves the best visualization results. For example, sending OSC messages from a DAW.

Different instruments work together to create a melody or rhythm. Our interpretation of this conversation is the annotation. Something beyond granular, repetitive, beat onsets (although they’re still important).

Is there an audio file format that supports adding OSC messages as metadata?

If not, I’d be curious to hear thoughts on adding annotations inside UE4…