Watch the The Major Scale: Key of C online guitar lesson by Rob Garland from Chord Navigator: CAGED Triads

Where do chords come from? We'll use the major scale as the basis for finding chords that are diatonic to the key, meaning all the notes in the chords come from that key and therefore that one scale. Example: In the key of C, begin on a C note and play C-D-E-F-G-A-B-C.