1. Absence of Consonance: Disharmonic music often avoids or minimizes the use of traditional consonant intervals such as perfect intervals (unison, octave), perfect fifths, and major/minor thirds. Instead, it emphasizes dissonant intervals like minor seconds, major sevenths, and tritones, creating a sense of tension and dissonance in the music.
2. Unconventional Chord Structures: Disharmonic music often employs unusual or unresolved chords that deviate from typical functional harmony. This might involve the use of extended chords, added tones, altered chords, or polychords, which create a sense of instability and ambiguity.
3. Cluster Chords: Cluster chords, which involve stacking multiple notes without regard for traditional voice-leading rules, are a common feature in disharmonic music. These clusters create dense, dissonant textures that depart from conventional harmonic structures.
4. Atonal Melodies: Disharmonic music frequently includes atonal melodic lines that lack a clear tonal center or hierarchical organization of pitches. These melodies often employ intervals that are unusual in tonal music, such as augmented seconds or diminished thirds, resulting in a dissonant and unpredictable melodic contour.
5. Exploration of Microtones: Some disharmonic music ventures into the realm of microtones, which are pitches that fall between the traditional twelve semitones of the chromatic scale. The use of microtones further expands the range of available dissonant intervals, creating a unique and distinct sound.
6. Avant-Garde Techniques: Disharmonic music often incorporates various avant-garde techniques such as aleatoric elements, unconventional instrumentation, extended instrumental techniques, or the use of electronic manipulations. These techniques contribute to the dissonant and experimental nature of the music.
Disharmonic music challenges conventional notions of harmony, tonality, and melodic structure, embracing dissonance and experimentation to create new sonic experiences. Composers who employ disharmonic techniques include Igor Stravinsky, Arnold Schoenberg, John Cage, György Ligeti, and many contemporary composers exploring new frontiers of musical expression.