Ch 8: Applications of perceptual organization Principles to Music Theory Flashcards
Polyphony
A musical texture containing several independent voices (parts, lines, melodies) simultaneously.
Counterpoint
The coherent combination of distinct melodic
lines in music.
Auditory scene analysis
the process by which the auditory system parses the incoming sonic waveform by extracting its spectral components and by segregating or integrating these components according to criteria such as proximity, similarity, closure, good continuation, common fate, and belongingness in order to form a correct description of the actual acoustic environment.
voice-leading
Voice-leading refers to the goals that govern the
behaviour of individual voices
What are the goals of voice-leading rules?
The goal of the rules is to create two or more
perceptually distinct parts, which requires:
a) Clear auditory stream integration within each part
b) Clear auditory stream segregation between the parts
Huron (2001suggested that most rules of voice- leading can be derived from experimentally established perceptual principles.
what are the principles?
• 6 core principles:
- toneness (perception of pitch)
- temporal continuity
- minimum masking (concept of critical bands)
- tonal fusion
- pitch proximity
- pitch co-modulation
Toneness principle
Sounds that have unambiguous pitch evoke stronger auditory images
How do we produce events with strong toneness?
▫ Frequencies above 5000 Hz tend to sound like
indistinct “sizzles” devoid of pitch
▫ Low frequencies sound like deep rumblings.
Pitch weight
- Pitch weight (index of pitch clarity) varies with frequency
- Average pitch of instrumental music (around D#4) is close to the maximum pitch weight
Temporal continuity
Clear auditory stream integration within each part
- Temporal continuity
▫ Auditory streams are best evoked by continuous or
recurring sounds
In musical practice, this principle is followed by:
▫ Designing instruments to maximize the duration of produced sound
▫ Avoiding rests
▫ Avoiding overlapping resonances
Rule of Chord Spacing
• b) Clear auditory stream segregation between the parts
• 3. Minimum masking principle
▫ To minimize auditory masking within some vertical sonority, approximately equivalent amounts of spectral energy should fall within each critical band
▫ The width (frequency range) of the critical band decreases with increasing frequency
Consonance
▫ Perfect (P1, P5, P8; P4?): greater degree of harmonic
spectral overlap = greater perceptual fusion
▫ Imperfect (m3, M3, m6, M6): lesser degree of harmonic
spectral overlap but still not much interference within critical bands = lesser perceptual fusion but low sensory dissonance
Sensory Dissonance:
vs.
Syntactic Dissonance:
interference within critical bands between fundamental AND/OR other partials, causing a physical sensation of tension or roughness caused by beating
element of musical syntax defined as tense within a musical culture, requiring conventionally defined resolution
Rule of Avoiding Unisons
• b) Clear auditory stream segregation between the parts
• 4. Tonal fusion principle
▫ The perceptual independence of concurrent tones is weakened when their pitch relations promote tonal fusion.
▫ Unisons, octaves, and fifths fuse the most readily.
• Fusion of concurrent tones is more likely if spectral content conforms to a single hypothetical harmonic series
▫ Fusion between concurrent tones of different parts should be avoided.
Pitch proximity rules:
Common Tone–Pitches common to 2 chords should be retained in the same
voice.
Nearest Chordal Tone—A part should move to the nearest available pitch
Conjunct Motion—If a part must change pitch, move by step
Avoid leaps
Avoid part-crossing—-Simultaneous chords should retain their vertical order (e.g.SATB, not ASTB, SABT, or STAB)
Avoid part-overlap
▫ A part should not go higher (or lower) than the part above (or below) it was on the previous chord (e.g. if the soprano has A4 in a chord, the alto should not go above A4 in the following chord ; if the bass has F#3 in a chord, the tenor should not go below F#3 in the following chord)
