This is not to solicit help, but to show off what I did with all the help I have received!
SoundToLights d-rives lights from music. I am still not sure that the Fourier is the way to go, as octaves might be better off replaced by frequency range filters, but I don’t know how to do that yet!
It was designed to be run on my light boxes, down a serial line, and extended to run with DMX using an ENTTEC DMX box. I tried to run it from an RS-485 box, but it didn’t work (though the code is still there!)
Many thanks to JAL whose audio-gathering software I am most grateful for,
and to Charles on ADUG whose Fourier stuff I am using with pleasure.
I don’t know whose work Serial3 is, but it has been a wonderful thing to have for many years.
The programme is available for interest, delight or masochism, on
https://59b7770ca3fb18e4e90d-52e2682744779750b5103bbecf998085.ssl.cf2.rackcdn.com/SoundToLights.zip