How to stem plot frequencies of an audio file?

I've been trying to audio read a file and then to plot the frequency on the y axis but I've had no luck. This is what I'm getting

But I need to get this

Here's my code

[data,Fs]=audioread('mysn.wav');
sound(data,Fs); % see what it sounds like */
N=length(data)
n=0:N-1;
x=transpose(data);
X=fft(x);
X_mag=abs(X);
z=max(X_mag);
N_2 = (N/2);
gh=find(X_mag(1:N_2)>10543)
gk=gh.*(Fs/N)
stem(gk)

[Geoff Hayes]

Jim - in the second figure, there are twelve distinct chords whereas in your figure there appears to be twelve sets of chords where each set may contain duplicated ones. What happens if you try to plot the unique chords as

 stem(unique(gk));

How does your figure look then?

[Jim Sun]

This still gives me the same stem plot. Here's the audio file

The values are actually not duplicate as they have a very minor difference. I'm trying to find the frequency of each key pressed. in this case I pressed 12 keys and created that wave file, but apparently there's a leakage that causes multiple frequencies to be plotted that are very close to each other.