Music Theory Approaches: 1. Tonality

This is the first of a series of threads devoted to various approaches to music theory and harmony. Tonality Rameau probably wrote the first book completely devoted to tonal harmony, in 1722. Since then not much has changed. There are some new innovations, though, which have appeared recently. Leonhard Euler (1707-1783) proposed his "Euler plane" about the same time as Rameau was writing his treatise. He made a grid, and placed fifths on the horizontal axis, and major thirds on the vertic [...]