Turn music theory into something you can actually play — on guitar or piano. Circle o Fifths is the fastest way to find the chords in any key, learn the scales to solo over them, and write your own songs. A handy practice tool that's a game changer for learning songs, writing your own, and finally understanding how chords fit together. NEW in 2.2: A Scales tab — see any scale on the guitar fretboard or piano keyboard, color-coded by degree, with the five CAGED shapes, full-neck patterns, and…