Thanks Michael, that I didn’t think about.
The equaliser bar, I made as following, make a solid about 50 pixels width and 300 pixels high.
Drag the anchor point to the bottum of the bar, and then pickwhip the scale to the output of your sound keys layer. Then copy paste this
temp = thisComp.layer("soundkeys").effect("Sound Keys")("Output 1");
[value[0], temp, value[0]]
over the expression code.
As a bonus I’ve made a copy of the solid, deleted all the expressions so the solid without animation, added a gradient layers style (red-orange-green) and used that as a mask for the animated sound bar below it.