Rec got it right. Human hearing and human music is not linear, but logarithmic in nature. Think about it. As an example, there are eight notes and twenty integer frequencies in the 20Hz to 40Hz octave. There are still only eight notes, but 10,000 integer frequencies in the octave from 10,000Hz to 20,000Hz. A good frequency response graph will highlight the musically relevant note info and lessen the visual impact of the less important integer frequency data.
Logarithmic Frequency response graphs
Why are frequency response graphs always charted on a logaritmic scale?