There is still something we need to do ourselves. I don't see how a computer software can identify a root note in a loop that may not even contain this certain root note.

I'm positive that computer software can identify the root note of an entire song. It even might recognize a key change. But I doubt it to be 100 percent of all cases.

A good example is the theme of the C Jam Blues. What is the root note of that theme? It fits many keys. You only have the melody to figure out. You have the 12 different keys made from the only seven notes there are, as your music teacher once said smile. Then we have the seven modes.

Now comes the fun part. When you play the C Jam Blues theme, you remain on the same notes for the entire song, not minding that the accompaniment plays other chords. What would a software do, when you go from I to IV and V?

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