Once you’ve converted your audio to keyframes, look through the values of the keyframes. Determine what value you want it the light to be on during. Usually you’ll see spikes in volume with drum hits, so you should see an increased value every time this happens. So if you see that the keyframed number is 8 or higher at every drum hit, then you would use the value 8 like I did in the expression I provided.
In order to enable the expression, option-click (alt-click on pc) on the stopwatch of the opacity property on the layer you want to effect (the lightbulb I assume). This places some text in a box to the right of it. Delete that text and replace it with the expression I provided you. Change that 8 to whatever value you want. Note that the expression says whenever the keyframed audio is greater than “8” the light will be on. So at 9, its on, 10, it’s on, etc. Play with that number until you get it right.
Remember though, this will only turn the lightbulb layer on and off. If you are trying to make other things turn on and off at the same time, you’ll need to apply the expression to those layers as well.
“|_ (°_0) _|”
Sincerely,
George