For an audio-reactive visual, I start with what should change on screen. A low-frequency pulse might open a shape. A sustained sound might hold it there. Silence needs a useful state too.
That gives me a reason to choose particular measurements, rather than connect every available input and hope the result looks good.
Keep the signal path understandable
The basic path is audio input, analysis, control values, and rendering. In TouchDesigner, those values can drive a material, an animation phase, or a composite. OSC is one way to bring measurements in from another application.
A raw level reading usually needs some work before it becomes a good visual control. I set its useful range, smooth rapid changes, and decide how quickly the visual should respond and settle. Different controls can use different timing.
Leave room for quieter moments
A visual that reaches its maximum response at an ordinary listening level has nowhere to go when the sound gets louder. I want to try the controls with quiet passages, dense passages, and pauses, then adjust the ranges.
It also helps to keep a manual control available. That lets me check the animation independently of the audio analysis and compare changes without replaying the same track each time.
Street Bloom is the next test
Street Bloom has a fixed concrete wall and separate animated layers for chrome, cracks, a membrane, internal light, and residue. The concept phases and viewing loops are ready to inspect on the project page.
Live audio control is still planned. The next step is to connect a small set of measurements to those layers in TouchDesigner, then test the transitions and the final output in the intended space.
Check the complete output
A responsive patch on a laptop can behave differently through a playback system and projector. I would check the full path for delay, dropped frames, scaling, and what happens when an input disappears. A held value or a slow return to a neutral state may be more useful than a sudden blackout.
I use a similar separation of measurement and presentation in the studio audio dashboard.