A pure GeoNodes setup of a frame-by-frame scaler, here driven by audio. Your curve radius is scaled by a value set up by you, every frame, creating a pleasing and reactive effect.

Video demo and 2 and 3, 4, 5, 1 

A user-defined curve is scaled frame-by-frame. The curve radius itself is actuated every frame by the current value, be it audio or keyframe. The effect essentially is a simulation, driven by Geometry Nodes. 

There are two versions of the setup presented here, as example of various settings and styles. A psecial version with swirling particles emitting from the current height of the curve.

NOTE 1

(Since it is a concept demonstration, it is kept as simple as possible.) The GeoNodes trees are kept clean, the nodes are not contracted into nodegroups for easier readability and have detailed explanations.)

NOTE 2

(This setup comes in two versions. One is the main version. The seconf one is a special addition, where a particle emitter follows the created curve to create a swirl of particles. )

Enjoy and blend like the wind !

YOUTUBE 

INSTAGRAM