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In music theory, Terzschritt (German: third step) is the progression from one major chord to another major chord, or a minor chord to another minor chord by major third root movement. Additionally, and more specifically, it is a dualistic major third relationship, in which the ascending progression from a major tonic triad to major mediant triad is equivalent to the descending one between a major tonic triad and a flat subdominant minor triad. The major chord on the mediant is itself the Terzklang (De: third chord).