In Lesson 35 we learned how to build major triads. The fun thing about triads is that each triad has 3 different forms, called “inversions”. (You might be accurate if you interrupted me here to let me know that there is nothing “fun” about triad inversions – but that is neither here nor there…) This means that a triad can be written in one of three ways: root position, first inversion, and second inversion.
Root position is the most straight forward, with the tonic located at the bottom of the chord – in the bass. If you need a refresher on how to create a major triad in root position, you can refer to Lesson 35. To create the first inversion, start with the triad in root position, and move the tonic note from the bass to the top of the chord. In the first inversion of a major triad, the bottom note will be the mediant (3rd note) of the major scale. Check it out in the graphic below.
Can you guess how second inversion is created? Here is a hint: Second inversion is created by starting with first inversion, and moving the bottom note to the top of the chord. The bottom note of the second inversion of a major triad is the dominant note (5th note) of the major scale.
As you can see in the graphic above, the first inversion can be denoted by using a 6/3 and the second inversion can be denoted by using a 6/4. These numbers indicate the size of the intervals that are present in the chord. This notation is commonly used in musical theory.