This could be a useful tool for determining what "magic frequencies" to bring out:

Although it's an Audio-to-MIDI application, I don't put tracks through it - rather for visually determining what key samples are in, such as what note the pitch of a noisey bass drum or snare is playing, or what notes make up an obscure sounding chord (if your ears can't really tell). The equaliser doesn't work except in altering the display of the analyzer, but may be useful in judging where to sweep on a real eq.
http://audioto.com/