Roman numeral code: V
Scale notes: 5, 7, 2
Attributes: strength, validation, affirmation
The transition from 1 to 5 and back serves to strengthen the sense of the key.
5 is an energy source. The 5 to 1 sequence generates power in music, more than any other transition. In the example tracks, listen how 5 reaffirms the key and the 1 harmony.
5's attributes come not from any special way the 5 chord is constructed; they come from the relationship between the 5 chord and the tonic note or chord or key.