home now...
more specifically, create a small rectangular shape layer.
add a repeater with its transform set to 0,-100 so that it goes up.
set the copies to 6 (though the expression will take care of this for you it helps to see how it looks.
then if you want it driven by audio, convert that tracks audio to keyframes using teh keyframe assistant and then add this expression to the repeater
a=thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider")
Math.floor(linear(a,1,20,1,6))