Tonality and Centricity. This block presents three structural fourths/fifths (E-B, D-A, D♯-A♯). These are filled in as Dorian tetrachords (E-D-C♯-B, D-C-B-A, D♯-C♯-B♯-A♯), each further elaborated with chromatic passing and neighboring tones. The structural fourths/fifths are connected by motivic intervals, 1 and 2.