Only just noticed how old this thread was. If you have a 631 then i have attached this demo prog. You need an mp3 call temp.mp3 located in your c:\ ie "C:\Temp.mp3" or it'll crash (No error handling still making the program) and if you have custom chars not saved (Not saved as boot) then they be overwritten. Also shows left and Right VU's and a progress. All selectable from the form in checkboxes.
I am only playing so i know its pretty week.
Also this uses the FMOD DLL. Its not mine you can find it at http://www.fmod.org. Very cool audio dll for all languages!!!
Am gonna do some experimentation on the spectrum over the next week or so. Thinking of having 24 smaller bars to give the spectrum and also gonna add a historysis (Dont care its spelt wrong!?!?) to soften the drops!!!