Don’t know a site like that.
But don’t you think you limit yourself in finding new tunes? If you start looking for tracks in let’s say A minor on a website that only shows you the tracks in A minor then you will potentially miss a lot of tracks that you might really like. But they are not in Aminor. Mixing in key can be really great but my advice would be to not only select tracks on key. Tracks that are not in key can be mixed. I think the best way is to select tracks that you really like and that are in the genre you are looking for.
But that is just my advice. Or just use Beatport or Traxsource to select tracks you like and then check for the key they are in. You can make the selection in your hold bin or shopping cart then.
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