Hi All, I'm looking for a computer program that will allow me to display simple sine waves on screen and add harmonics to them in variable quantities to simulate how sounds are affected by the relative strengths and frequency of the harmonics. I don't necessarily want it to produce sounds (though that would be nice) but the interactive graphics part would be essential - ie drag and drop a harmonic onto the main display and see the additive or subtractive result. I don't mind paying a modest sum. Many, many years ago I wrote a program in BASIC that could do this - years before Windows, in the days of DOS and CP/M - but I wouldn't know where to begin now. I have searched t'Internet but so far found nothing. Any help would be greatly appreciated. BTW, I know I could use an oscilloscope, but I'm hoping this would be more fun.