Pulling the micro and trying a 4013 clocked by the 555 and feedback between
the 2 flip-flops gives quite a pleasant pseudo-random sequencing to the 4
strings. Just have to hope it does not have a latch up state - I've
forgotten how to determine that, clocked through a few hundred cycles
without hickup.
For anyone else , in the future, where to put the ouput of the mic amp to
give a beat sync to the lights?