Measuring Hz and dB of a song

I am a senior at a local university. I am a biology major, my senior experiment is going to be playing music to plants to measure the germination and growth rates. One issue I am having is trying to get a range of frequencies and possibly intensities of the song. I was referred to this site by a coworker. I was wondering if you guys may have an idea on how I could do this. Any help is greatly appreciated.

You can get frequency data from the “Plot Spectrum” tool in the “Analyze” menu.
This tool has been significantly improved in the 1.3.12 version of Audacity.
Also, I’ve just posted an amplitude analysis plug-in here that may be useful: