A type of symmetrical fret that is based on a major third chord (augmented triad; hence the name).
Structure U. l. presented 3 main. species, depending on 3 Ch. forms of presentation of the sound material of the mode (basic tones of chords, melodic scale, group): chord, melodic, group. Chord U. l. characterized by the arrangement of 3 chords (usually of the same type in structure) along a series of major thirds; melodic U. l. – melodic. movement along one of the specific scales formed by dividing 12 semitones of an octave into three parts equal and uniform in structure (in semitones, for example: 3 + 1, 3 + 1, 3 + 1 or 2 + 1 + 1, 2 + 1 + 1, 2 + 1 + one); group U. l. – the use of specific scales in a mixed, “diagonal” (horizontal-vertical) dimension. Samples of 1 types of U. l.:
N. A. Rimsky-Korsakov. “The Golden Cockerel”. Action 1st.
H. A. Rimsky-Korsakov. “Snow Maiden”. Prologue.
O. Messiaen. Theme and Variations for Violin and Piano.
The term and theory U. l. belong to B. L. Yavorsky.
See Symmetric modes, Modal rhythm, Reduced mode, Whole-tone mode.
References: see at Art. Symmetrical frets.
Yu. N. Kholopov