Find the Key of C G Am F (Classic Pop Progression)
Score the twelve major and twelve minor keys against a list of chord symbols and show the best five.
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Result
About this tool
This page opens the chord key finder already loaded with one of the most recorded progressions in popular music: C, G, Am, F. As soon as the page loads it tests every major and minor key against these four chords and ranks the most likely matches with their scale-degree labels — the result below is computed live, not a static example.
C, G, Am and F are the I, V, vi and IV chords of C major, played in that order or any rotation of it (the same four chords also show up as vi-IV-I-V, I-V-vi-IV and other orderings in songs across pop, rock and worship music). The pattern is popular partly because every chord shares at least one note with its neighbor, which makes the transitions sound smooth even to an untrained ear, and partly because it lets a melody move freely between the major scale's brightest and saddest-sounding chords without ever leaving the key.
Swap in your own chords to analyze a different progression, or use the degree labels below to see exactly how C, G, Am and F function inside C major — the same four shapes transposed to any other root will produce an equivalent I-V-vi-IV progression in that key.
Example. C Am F G ranks 1. C major - 96%, with C as I tonic, Am as vi submediant, F as IV subdominant, and G as V dominant. A minor is second at 88%. In G major, F is marked outside key.
Limit. Only major and natural minor are scored, and only the top five are shown. The page reads chord symbols. It does not detect a key from audio.