Spectrum: bars that follow the song

A Spectrum fill draws the song's frequency bands as bars, a curve or dots, along a line or an arc.

Try this

  1. Press play with sound on. The bars rise and fall with each band.
  2. Click the bars and open Spectrum. Bars sets how many; Form picks Bars, Curve or Dots.
  3. Set Along to An arc for a dial, as on the Radial artboard.
  4. Drag Ghost up to leave fading copies of the last few beats.