Thanks, I’ll have to fix that. The first and last chords of the progression are not 7th chords. Somehow I inadvertently typed “I7″ on the first chord of all the major keys. (Notice that I didn’t do that for the minor keys.) Musical Scales. Scales and emotions. See also a post about the major scale modes and an intro to minor keys.
So maybe you want to write a song or an instrumental in a particular mood or style, and you’re feeling overwhelmed by all the scales. Here’s a handy guide to the commonly used scales in western pop, rock, jazz, blues and so on. I show each scale in two views: on the chromatic circle, and the circle of fifths.