So our 3 rd note would be a G#, but we can’t have that, since that note is not in the key of C. All of these notes are on the C major scale as well, therefore the second chord in the key of C is D minor. This gives us the notes D, F and A, which is the D minor triad. We have to lower the 3 rd to the flattened 3 rd. So our 3 rd note for would be an F#, but we can’t have that, since that note is not in the key of C major (not on the C major scale). This gives us the notes C, E and G, which is the C major triad, therefore the first chord in the key of C is C major. Now let’s calculate the quality of each chord in the key of C. Diminished triads (diminished chords) with scale degrees 1 b3 b5.Minor triad (minor chords) with scale degrees 1 b3 5.Major triad (major chords) with scale degrees 1 3 5.Confusing? Have no fear, we'll get to some examples shortly. If any note is not on the C major scale, we’ll have to flatten it to make it a note that can be found on the C major scale. This means that starting from each root note, we’ll count out the 1 st 3 rd and 5 th degrees along the major scale of that given root note. The C major scale has 7 notes, each with a corresponding scale degree:īut how do we know which chord will be major or minor? Starting from a given root note, we need to form its triad in a way that leaves the chord constructed only from notes that can be found on the C major scale. Oh, if you're a beginner guitar player and lost track already, you'll want to get familiar with the major scale on guitar before continuing this lesson. The chords in C will root on the notes along the C major scale, since all chords in a major key are formed by notes from their respective diatonic scale. Why are these the chords in the key of C major? (the theory) I = major, ii = minor, iii = minor, IV = major, V = major, vi = minor, vii = diminished Popular chord progressions in the key of C Progression TIP: The chords of any major key will always have the following major-minor pattern: