C
Every chord is based upon a specific formula which relates back to the major scale after which it is named (revise Lesson 14). The formula for a major chord is I - III - V, hence the C major chord consists of the first, third and fifth notes of the C major scale, i.e., C - E - G. As you know, a chord must contain at least 3 notes, and any of these three may be repeated. In the open C chord illustrated there are 3 E notes, 2 C notes and 1 G note.
Now consider the D major chord, which is constructed from the D major scale:
The same formula applies (I - III - V), so the notes of a D major chord will be D - F# - A. (Play an open D chord and check for yourself).
It is important for you to revise all major scales studied so far. Once you have done this, construct the following major chords:
Notes in The Chord