TetraNa progression — root and its three inversions
Harmony is when opposites meet and circles close in unity — while remaining open-ended. The TetraNa progression exemplifies this quite visibly in its relative simplicity.
TetraNa, as tetratonality, spans only four notes, the fundamental and initial three overtones of the harmonic series. This progression rounds off the Tonalibus catalogue of tonalities, after growing to a considerable number of entries. It unifies the overtone foundation with pattern progression, full and partial, progressive and regressive, as well as anchored and to some extent also not anchored.
Harmony in its widest sense includes and remains open to everything and all. This progression stands for how the Tonalibus catalogue is to remain open-ended after reaching some level of completeness of something that in its entirety will always escape complete human grasp, will always be greater and go further — harmony, here in its expression as myriad of anchored tonalities.
Progression / inversion sound samples
Inversions are not tonalities as such but underlying roots of tonalities. Therefore they facilitate progressions and modulations.