The use of astrodynes takes much of the guesswork out of chart interpretation by mathematically determining the relative power in a horoscope. Simply put, astrodynes allow a greater precision in birth chart interpretation.Previously, the chart ruler was considered to be the ruler of the Ascendant. Now, the strongest planets, signs, and houses can easily be determined, leading to more accurate assessment of vocation, temperament, and compatibility. The level of harmony or discord will indicate the fortune that can be attracted by each factor.There is a difference between power, which is a potential for action, and harmony, which is the effect of the action. The amount of strength in the chart will show how insistent are the desires, or specific areas of life. Whether they express in harmony or with difficulty has little to do with the amount of power they have. There- fore, the first step in a better understanding of how to use astrodynes in a birth chart is to understand what power is in a chart, what harmony is, and the difference between the two. The author explains these differences and focuses on the interpretation of astrodynes, including specifics about each planet, house and aspect.