I've opened the door towards using Fourier analysis (FFT - Fast Fourier Transform) in my upcoming research. Thanks to an old friend from Thailand, I managed to get freeware called Audacity late last night - and tested it with my voice:
This is going to be interesting once I get started on using it for instruments. The questions that arise are 1. how far I can use it in musicological research without needing external mathematical expertise in interpreting the analysis, and 2. how sensitive current technology is towards analyzing sounds which are pretty close to start with. One way or another, this will be an interesting adventure.