Psychology of Music

1
Psychology of Music
Dirk Beer
2
Overview

• Components of music pitch, loudness, duration,
  timbre
• Organization of music harmony, melody, rhythm,
  tempo
• Music and the mind Shepard illusion, Tritone
  paradox
• Musical conventions -- arbitrary or natural ?
• - Tempo
• - Consonance / dissonance

3
Components of Music
Perceptual Acoustic Musical

• Tone
• Loudness
• Note value
• Timbre

• Pitch
• Loudness
• Duration
• Timbre

• Frequency
• Amplitude
• Timing
• Overtones

4
Pitch

• How high or low tones are
• Related to frequency
• - modulation of air pressure (eg. by a string)
• - measured as cycles per second (Hz)
• human hearing 20 - 20,000 Hz
• piano 30 - 4,000 Hz
• Perceived pitch is roughly logarithm of frequency
  equal ratios are equal steps (12-tone scale)
• ltLevine S. graphgt

5
Pitch Perceptual Phenomena

• Octave equivalence a note doubled in frequency
  sounds similar to the original
• cross-cultural
• perceptual quality is chroma
• pitch chroma height

6
Pitch Perceptual Phenomena

• Absolute vs. relative pitch perception
• notes not tuned to the standard frequency sound
  very unpleasant to people with perfect pitch
• experiment name random piano notes
• two groups octave errors
• evenly distributed errors
• early musical experience

7
Loudness

• related to amplitude of sound pressure variation
• measured as dB
• loudness is logarithm of amplitude
• ltLevine Shefnergt
• loudness depends on frequency also
• ltpitch loudness demogt

8
Duration

• how long or short tones are
• measured in msec
• or
• measured by note values (whole, quarter, half
  notes)
• note value indicates number of beats, measured
  in beats per minute (bpm)
• example 60 bpm -gt quarter note is 1 second

9
Timbre

• what differentiates a note of the same pitch and
  loudness played on two different instruments
• color, depth, sound quality
• example saxophone sounds different than a
  trumpet
• related to purity vs. complexity of tones
• fundamental overtones (harmonics, partials)
• ltdraw string vibration modesgt
• fundamental frequency is perceived pitch,
• even if fundamental is missing!
• Missing fundamental illusion

10
Pitch relationships in music

• Harmony
• the pitch relationships between tones played at
  the same time
• harmonic interval (2 notes)
• chord (3 or more notes)
• triad (3 notes separated by a specific interval)
• Melody
• the relationship between tones played one after
  the other
• Consonance dissonance
• scale - a set of tones that fit into an octave
• example modern 12-tone scale
• example 9-tone scale
• interval - distances between pairs of tones in a
  scale
• example 3rd, 5th, etc.

11
Musical Illusions

• Shepard illusion - perception of continuously
  rising tone
• local vs. global
• Eschers continuously ascending staircase
• Tritone paradox - does pitch increase or
  decrease?
• physical stimulus is ambiguous
• perception based on linguistic experience

12
Temporal relationships in music

• Rhythm - the feeling of movement in music
• - the basic beat
• - the beat's accented pattern
• - the temporal sequence of notes of various
  durations
• - rubato "pushing" and "pulling" the beat
• Tempo - the overall speed of the music (beats
  per minute)

• What is the right tempo?
• composers markings often not helpful
• example Mozart used fast metronome?
• ratios of tempos may be important (Levine,
  reading 10)

13
Musical conventions aesthetics

• What is the right tempo?
• Composers markings often not helpful
• example Mozart used fast metronome?
• Ratios of tempos may be important (Levine,
  reading 10)
• music performed with steady beat (tempo)
• listener biologically entrained to tempo
• tempo can only be varied in integral ratios?
• -gt case studies of 7 semi-isolated musical
  cultures
• tempo in integral ratios most of the time
• - but no indication of what the distribution of
  ratios was -

14
Musical conventions aesthetics

• What determines consonance-dissonance?
• (consonant pitch interval)
• (dissonant pitch interval)
• Pythagorean theory - integer ratios of frequency
• simpler ratios are more consonant
• but,
• small deviations from ratios dont matter
• different intervals considered consonant at
  different times in history
• Helmholtz theory - consonant if tones share
  harmonics
• doesnt explain how pure tones can be consonant
  or dissonant
• (no harmonics) 

15
Musical conventions aesthetics

• Kreitler Kreitler theory (reading 9)
• musical intervals have origin in overtones
• music began with one tone
• new tones added when this became boring
• most common, easily heard overtones adopted
  first
• consonance-dissonance based on cultural
  experience

16
Summary

• Musical conventions are largely arbitrary, yet
  must be followed closely for music to be
  aesthetically acceptable (within one culture)
• e.g. consonant-dissonant intervals
• Theories of musical aesthetics must take into
  account perceptual phenomena as well as physical
  stimuli
• Because perceptual phenomena depend on context,
  scientific studies should use real music as well
  as isolated stimuli.