Hmm... I don't see any series resistors in the video or on your schematic. And no bypass caps either, as Mike suspected. Could these problems be causing your flickering problems? It does not look how I expected either before or after the code change. With 4017, only 1 output should be high at any time, but it looks like they are all on at the same time, as if the count being sent to them is random every time. I expected to see a single led lit, moving left or right as the volume of sound in that equaliser band varies.