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• Music as a way to express thoughts and emotions
– Pythagoras: Numbers and musical intervals
– Some clinical psychologists practice music
therapy
Music and Speech
Perception
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Music
Music (cont’d)
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Frequency Range of Music
• Musical notes
– Sounds of music extend across frequency range:
25–4200 Hz
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Pitch Perception
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• Physical Dimension: Frequency
• Psychological Experience: Pitch
Differences in pitch
• Ratio of frequencies
• 1000 Hz to 1500 Hz
– Increase of 500 Hz
– Increase of 50%
• 3000 Hz to 3500 hz
– Increase of 500 Hz
– Increase of 17%
• Demo: 1000, 1500, 2000, 2500, 3000, 3500
• Equal steps in perceived pitch
– log frequency
– Not linear frequency
– (at least with higher frequencies)
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Western Musical Scale – Log Frequency
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Music (cont’d)
• Octave: The interval between two sound frequencies
having ratio of 2:1
– Example: Middle C (C4) has fundamental
frequency of 261.6 Hz; notes that are one octave
from middle C are 130.8 (C3) and 523.2 (C5)
– There is more to musical pitch than just frequency!
•
•
•
•
•
E’s: 41.2
82.4
164.8
329.6
659.2
F’s: 43.7
87.3
174.6
349.2
698.5
E-F (Separated by Semitone) Constant ratio 1:1.06
True for all pairs across range
Web Demo
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Music (cont’d)
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Tone Height and Chroma Helix
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Music (cont’d)
• Tone height: A sound quality whereby a sound is
heard to be of higher or lower pitch; monotonically
related to frequency
• Tone chroma: A sound quality shared by tones that
have the same octave interval
• Musical helix: Can help visualize musical pitch
• As frequency increases
– Tone height increases
– Tone chroma cycles
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Music (cont’d)
• Musical instruments: Produce notes below 4 kHz
– Listeners: Great difficulty perceiving octave
relationships between tones when one or both
tones are greater than 5 kHz
• Dyads: Pairs of notes played simultaneously
• Chords: Three or more notes played simultaneously
– Consonant or dissonant
– Consonant: Have simple ratios of note frequencies
– Dissonant: Less elegant ratios of note frequencies
– Web Demo
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Consonance and Dissonance
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• Consonance: Simple ratios of notes
– Dyad Example
• Major 5 th: 3:2
– Chord Example
• C Major: 6:5:4
– Many common harmonics
• Cultural differences
– Research on music perception: Western vs.
Javanese
– Javanese culture: Fewer notes within an octave;
greater variation in note ’s acceptable frequencies
– Even young infants can learn to distinguish
sounds in their native scale
• Dissonance: Less elegant ratios of notes
– Dyad Example
• Augmented 4th: 45:32
– Chord Example
• Augmented C: 32:25:20
• Web Demo
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Music (cont’d)
Music (cont’d)
• Melody: An arrangement of notes or chords in
succession
– Examples: “Twinkle, Twinkle Little Star, ” “Baa Baa
Black Sheep”
– Not a sequence of specific sounds: Sensitive to
change, (i.e., change in octave)
– Notes and chords vary in duration: Tempo; fast or
slow
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Music (cont’d)
• Rhythm: Not just in music!
– Lots of activities have rhythm: Walking, waving,
finger tapping, etc.
– Bolton (1894): Experiments with sequence of
identical sounds, perfectly spaced in time, but no
rhythm; listeners reported hearing first sound of
group as “accented,” while the rest remained
unaccented
– More examples: Car, train rides
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