Have you ever wanted to find out the chords played in a song, but couldn’t because it’s not a famous song or nobody has put them up on the internet or its in a different language? I have a decent sized mp3 collection and ever since I picked up the guitar, I have been hunting for chords for many of these songs. So I was surprised to find that there is a free open-source project titled CLAM that has developed a software called Chordata that can actually analyze an MP3 and tell you all the chords in the song. Moreover, it also displays the chords in time with the music so that you know where the chords change.
Website : http://clam-project.org/