Roman numeral code: IV
Scale notes: 4, 6, 1
Attributes: forward motion, confidence, accomplishment
4 moves music forward. It represents courageous action toward a new plane of existence.
4 is a venturing out from 1. But whereas the transition 1 -> 5 was safe and solid, because an easy return was assured, the transition 1 -> 4 represents a less secure jump, because there is less of a pull from 4 back to 1.
The 4 back to 1 transition seems to require energy rather than giving it back, as 5 -> 1 does. Music gets around this situation by returning from 4 through 5 back to 1. Very rarely does harmonious music jump back to 1 directly from 4. Some exceptions are the “amen” at the end of hymns (the so-called 'plagal cadence'), and many rock and blues progressions, in which 5 -> 4 -> 1 is a characteristic cadence ('cadence' refers to the ending of a musical phrase).