Frequency Compactor

I am working on an automatic guitar tuner for a class project. I am looking for a chip to compare a guitar's audio signal to a fixed frequency oscillator signal. Ideally, I am searching for a chip that takes an input signal (A)and compares its frequency to the desired frequency , specified via oscillator (B) embedded in the chip whose frequency can be adjusted through an external resistor and capacitor. Ideally, this chip would produce three different outputs. One for frequency of A greater than the frequency of B, one for frequency of A less than the frequency of B,and one for when the two frequencies are equal. If such a chip is not available, do you have a similar chip which has no embeddence oscillator , but instead takes two input signals and compares thier frequencies to generate similar outputs described earlier. If these chips are not available, please let me know if you have other frequency comparator options, such as similar chips with fewer outputs or combinations of chips which can be wired into a frequency comparator circuit. Also, please let me know if you have other suggestions for how to solve this problem.