In 12-TET, you don’t define your intervals by tidy ratios of whole numbers. Instead, you divide up the octave into twelve equally-sized semitones (the interval between two adjacent piano keys or guitar frets). You then add semitones together to make all the other intervals. To go up a semitone from any note, you multiply its frequency by the 12th root of two. To go down a semitone from any note, you divide its frequency by the 12th root of two. If you go up by an octave (12 semitones), you’re multiplying your frequency by the 12th root of two 12 times, which works out to two.
Soundfly’s six-week beginner harmony course, Unlocking the Emotional Power of Chords, will show you how to craft compelling chord progressions in your music. We’ll analyze the chords used in music from across the contemporary landscape, and equip you to use them in your own productions and compositions. You’ll be challenged to write your own mood-setting music by creating tracks for topliners, TV ads, film trailers, and more, and get personalized weekly feedback on your work from an expert mentor. By the end of this course, you’ll be able to harness more interesting chord progressions to provoke powerful emotional reactions in your listeners.