Ok, I put together a series that some of you may find interesting

http://soonlabel.com/cgi-bin/yabb2/YaBB.pl?num=1231472075

http://tinyurl.com/9hzzlt

I did what Carl suggested and played around with pure sines, and also with pure triangles.
I only had time to do this in 12 TET.

By using an oscilloscope program I captured the FFT spectrum of C major C minor and C sus 4th.
There is a music example as well.

I also did the same with a triangle wave.

From a screen shot of cool edit you can see the beating or roughness of the chord. However, the lack of harmonics do not make a difference to me in the perceived consonance. In fact is you load the sine example in cool edit it looks pretty much the same as the triangle version.

This is all I had the time to do - any suggestions for exploration?