How to build major chords
All basic, major triad* chords are built using a root note plus the major 3rd and perfect 5th above that note.
Major 3rd = 4 half steps above root
Perfect 5th = 7 half steps above root
A half step is simply a measurement that means the next closest note. So, if you look at a piano keyboard (as pictured below) you can start on any note, and if you go to the next closest, then you have moved a half step.
Let’s have a look at a couple examples
Using this idea and starting on the note ‘C’ as our root note, let’s go ahead and build a C major chord.
Root = C
C + 4 half steps (major 3rd):
1) C → C# 2) C# → D 3) D → D# 4) D# → E
C + 7 half steps (perfect 5th):
1) C → C# 2) C# → D 3) D → D# 4) D# → E 5) E → F 6) F → F# 7) F# → G
C major chord = C E G
Let’s try it again, this time starting on ‘D’.
Root = D
D + 4 half steps (major 3rd):
1) D → D# 2) D# → E 3) E → F 4) F → F#
D + 7 half steps (perfect 5th):
1) D → D# 2) D# → E 3) E → F 4) F → F# 5) F# → G 6) G → G# 7) G# → A
D major chord = D F# A
Try building out other chords on your own using the same steps from above. Just pick a note to be your root and see what you get. Remember, a sharp note (F#) can also be a flat note (Gb). They are enharmonic equivalents (meaning they sound the same but are technically different).
Where to go from here?
Major chords are only one part of the palette of colors available for building harmonies and songs. Understanding what they are and how they function can free you to become creative in your own way instead of just copying what you learned from a song.
Taking ideas from others is a great place to start, but understanding what is going on and why it works opens up many more possibilities. At the end of the day, always trust your ear, but knowing what you’re hearing and expanding what you know will give you many more ideas as you develop your skills.
*triad – a collection of 3 different notes, ie: C E G for a C major chord