​In review, the scale degrees and names of the major scale thus far are:

  • I            Tonic
  • ii               
  • iii                
  • IV            Subdominant
  • V            Dominant
  • vi                  
  • viio         
The chart below shows opening and closing progressions using the primary triads of the scale and the chord map illustrates progressions towards the dominant (V) and back to the tonic (I).
 OPENING            CLOSING
  • I-V-            V-I
  • I-V-            IV–I
  • I-IV-            IV-I
  • IV-V-            V-I​
The remaining triads of the scale are called secondary. The secondary triads provide tonal variety and give color to the harmony. They will be the next topic. 
  
In the staff below make a chordmap for the chords of the diatonic scale in the key of D major. Fill in the notes and label the name and number for each triad.