Konusstufen
Konusstufen, German for “consonant degrees,” is a term used in music theory to describe the subset of a diatonic scale that is considered most consonant with the tonic and thus central to tonal harmony. The concept helps analysts identify which scale degrees most strongly underpin the tonal center when constructing chords and shaping progressions.
Typically, the primary Konusstufen are the tonic (scale degree 1), the mediant (3) and the dominant (5).
Examples in a key such as C major illustrate the idea: C (1), E (3) and G
Usage and variation: The exact definition of Konusstufen varies by author, historical period, and pedagogical tradition.