Trying to infer what you want from your unintelligible ramblings, I think what you want is:
1. Attach a microphone to the Arduino.
You will require an amplifier to boost the signal to a level the Arduino can sense. You should look in to op-amp microphone pre-amplifiers. There are plenty of resources on the web for them.
2. Find the frequency of the signal.
There will be many many frequencies present in the signal, not just one. You will need to sample a clip of audio from the microphone and do a Fast Fourier Transform on it. This will give you a list of frequencies present in the signal and their amplitudes.
3. Light an LED depending on the frequency.
You can use the list of frequencies provided by the FFT to find the frequency that has the greatest amplitude. This is the peak frequency, and can be used to make decisions, like is it above or below a threshold? Is there no clear peak frequency? Etc.
So, you have some reading to go and do:
- Read up on attaching a microphone to an Arduino using a pre-amp circuit.
- Read up on Fast Fourier Transforms, and find some Arduino code to do it (hint, look for fix_fft).