Guitar Chord Matcher
Today I was trying to figure out the chords in a song (Katie Reider’s awesome “Slowing Down for the Silence”). I figured out a couple chords, but was having trouble guessing some of the others.
So I whipped up this little web application. You tell it a chord in your song and it will tell you all the major keys where you can find that chord. Using that knowledge, you can try the other chords in the key and see if they fit the song you’re playing. I’m pretty sure Katie’s song is in D major.