In any key it is possible to build chords on each note of a scale. This means that for every major scale there are seven possible chords which can be used for creating guitar parts and harmonising melodies. These seven chords are called scale tone chords. It is common practice to describe all the chords within a key with Roman numerals. Here are the seven scale tone triads (three note chords) in the key of C major.
Now play the seven scale tone triads from the key of C as arpeggios. The ascending pattern in bars 1 to 4 begins on the root of each new chord, while the descending pattern in bars 5 to 8 begins on the 5th of each new chord.