A harmonic progression is a sequence of numbers where the reciprocals of the terms form an arithmetic progression. For example, if the terms of a harmonic progression are a, b, and c, then the values 1/a, 1/b, and 1/c will be evenly spaced. This means that the difference between consecutive terms in the sequence of reciprocals is constant. Harmonic progressions are often used in mathematics and music theory. In music, they can help in understanding the relationships between different notes and chords. The concept is also applied in various fields, including physics and engineering, where it can describe certain types of wave patterns.