I have a 100hz sine wave that I am adding harmonics to with a tube/saturation plugin. I want to experiment with how different the harmonics look vs the fundamental to see what the simulation is doing to add/create harmonics that weren't there. I haven't tried to look at the output on a scope as it makes sense the scope can only show all voltages combined so it would not be possible to analyze a specific harmonic to see its shape compared to the original. For example how different will a 2nd harmonic (octave) look.
The first obvious though is to try to get a tight filter on the 2nd harmonic and try to view it on a real scope. Then test various waves ie sine saw square triangle. Maybe someone knows a better more accurate way to isolate a frequency and view its shape. The spectrum analyzer only allows so much. Even a square wave looks look a sine. The second image is an example of how what I want to see isolated on a scope.