It's possible to use Machine Learning techniques to cluster songs into musical-scale groups? I mean: "this song was written in C"... or "this song was written in Am" etc. I made a fast search about the subject and I found no software that can do this. If you know some software, or research (academic papers), related to that subject, could you link it here for me? I'm very interested in that subject but I'm not sure from where I can begin. I have a little experience with Random Forests and Neural Networks, maybe I can accomplish the classification task with one of those algorithms, but, again, I'm not sure which kinda of features I should pass to the algorithm. Thanks in advance.