WHAT KEY AM I PLAYING IN?
by STEVE R
I WRITE A LOT OF INVOLVED CHORD PROGRESSIONS FOR ORIGINAL JAZZ COMPOSITIONS. HOW CAN I TELL WHAT KEY THE SONGS ARE IN THAT I AM WRITING?
Please visit Music Chord Progressions for an explanation of major chord progressions.
You can find an explanation of minor chord progressions here: Minor Chord Progressions.
Of course, they key CENTER can change in a song without a formal change of key signature. An easy way to tell if the key has temporarily changed is to look for Dominant 7th chords. Since they appear in only one position (V) in a progression, they are an infallible determinant of key.