Lecture 3 Perception: pitch, rhythm and timbre

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Lecture 3Perception pitch, rhythm and timbre

• MUSI 1911/2
• Introduction to the
• Psychology of Music

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Overview

• Music Perception
• The notion of musical parameters pitch, rhythm
  and timbre
• 3 Examples of perceptual experiments
• Perception, representation and responses
• Shortcomings and biases
• Summary

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Music Perception

• The study of how we organise musical sounds e.g.
• we hear pitch (not frequency)
• we hear relationships between pitches
• melody
• intervals between pitches
• harmonic relationships (tonality)
• What processes lead to such organisation?

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The notion of musical parameters

• Pitch
• Rhythm
• Timbre
• Separate dimensions of music

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Pitch

• pitch is that auditory attribute of sound
  according to which sounds can be ordered on a
  scale from low to high (ANSI)
• BUT relationships between pitches are more than
  just one-dimensional
• octave equivalence (all As are equal)
• more dimensions?

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Rhythm

• Temporal Patterns
• succession (what order are these events in?)
• duration (how long is this event/these events?)
• grouping (where are the boundaries between groups
  of successive events)
• metre (is there a cyclic pattern of stronger
  and weaker events)

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Timbre

• Timbre is that attribute of auditory sensation in
  terms of which a listener can judge that two
  sounds similarly presented and having the same
  loudness and pitch are dissimilar.
• American National Standards Institute (1960). USA
  Standard Acoustical Terminology
  (IncludingMechanical Shock and Vibration)
  S1.1-1960 (R1976). New York American National
  Standards Institute.
• Timbre has always been the miscellaneous category
  for describing the psychological attributes of
  sound, gathering into one bundle whatever was
  left over after pitch, loudness, and duration had
  been accounted for.
• Dowling, W. and Harwood, D. (1986). Music
  Cognition. New York Academic Press.

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• Different levels of timbral description
• 1. "the expressive variations
  available to performing musicians" (45)
• 2. "commonalities shared by all
  oboe tones, all bowed violin tones, all timpani
  tones, and so on (45)
• 3. Broader family distinctions or
  method-of-production distinctions "percussive
  instruments, whose behavior is determined
  completely at the instant when they are set into
  motion, and instruments, such as blown and bowed
  instruments, whose behavior is controlled
  continuously. (45)
• Krumhansl, C. (1989). Why is Timbre So Hard to
  Understand? In S. Nielzen and O. Olsson (Eds.),
  Structure and perception of Electroacoustic
  Sound and Music, 43-53. Amsterdam Excerpta
  Medica.

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3 Examples of perceptual experiments

• Krumhansl and Shepard (1979)
• looked at perceived relationships between a scale
  and subsequent probe pitches
• Parncutt (1994)
• looked at the way in which we sense the pulse
  of a musical rhythm (experiments and a model)
• Grey (1976)
• looked at perceived similarity between
  instrumental tones at the same pitch

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Krumhansl and Shepard (1979)

• Materials (Exp. 1)
• Subjects listened to context (scale) followed
  by a probe tone a single pitch
• Probe tones were all the chromatic notes between
  middle C and C an octave up
• Contexts were ascending or descending C major
  scale (below or above the range of the probes)
• Task
• Rate how well the last tone completed the
  sequence on a scale of 1 - 7

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• Results
• Group 1 listeners
• Cs rated highly (no difference)
• Notes of tonic triad rated slightly less highly
• Notes in-scale fit better than non-scale notes
• Group 2 listeners
• Cs rated highly (small difference)
• Group 3 listeners
• Cs rated differently (by literal pitch distance)
• Subject 24
• Like group 1 only more so

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• Conclusions
• there is a hierarchy of pitches for tonal music
• some people have internalised this hierarchy
  better than others (representation)
• perception is related to internal representations
  of relationships between events
• it is this representation (or schema) which is
  hierarchical
• we hear the same pitches, but perceive them
  differently

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Perception, representation and responses

• Researchers often attempt to show a clear
  relationship between a perceptual task and a
  mental representation or process
• It is often assumed that we need to understand
  perceptual processes and representations before
  dealing with responses to music (such as
  emotional ones)

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Shortcomings and biases

• Much perceptual work focuses on tonal western art
  music (or patterns that resemble it)
• Little work looks at relationships between pitch,
  rhythm and/or timbre
• Many tasks still far from real musical situations
  and events

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Summary

• Perception
• the first stage in apprehending musical
  structures
• related to mental structures
• precedes emotional or other responses
• often studied using controlled experiments
• often musical parameters are isolated in rather
  artificial ways