I have just recently (today) developed a spectrum analyzer as part of OpenScript2.0. It works pretty nice and is a step up from other spectrum analyzers i've done in the past.
If you would like to view the analyzer, you'll need to download and install OpenScript2.0, and then download the analyzer from the SDK. overall dl is about 4 megs. OST2 itself is 400k or so, but the spectrum analyzer includes a song, so it's pretty big. (My language fits onto a floppy disc )