Music, Physics & Emotion
|Topic||Wave physics/the physics of music|
|Program||Brown Science Prep|
|Developed by||Nihaal Mehta|
|Developer Type||High school students|
Overview / Purpose / Essential Questions
How does the nature of sound lend emotion to music?
Performance / Lesson Objective(s)
1. To describe sound physically as being composed of compressional waves
2. To identify properties of sound (pitch, intensity) as being functions of physical characteristics of waves (frequency/wavelength, amplitude)
3. To draw connections between features of music and the emotions they elicit
5-7 jump ropes
1 laptop/lesson group
Music has been described as the language of the spirit, an aspect of human existence that Darwin could find no evolutionary explanation for. And yet, it is profoundly elemental – a product of universal laws of physics. Understanding the nature of music as being composed of sound, and how that in turn affects how we feel, can help us understand the neurological basis for emotion, thought, and behavior.
1. Introduction video and conversation about music and emotion
2. Background on physics behind sound waves
3. How sound waves contribute to more complicated features of music
4. Brief discussion of how aspects of music can relate to the emotionality of the music
Introduction (11:00 - 11:15 am)
- Play clip from PBS movie The Music Instinct, from beginning to 2:55 (when the opening title appears)
- Brief discussion with students:
-Ask students to volunteer examples of songs that particular connect with them.
-Mentors, talk about songs that are like that for you.
Music and physics (11:15 - 12 pm)
What is sound? (11:15 - 11:30 am)
- Sound is oscillation – repetitive changes between two states – of pressure
- Particles are “pushed” repetitively, compressing them in some areas and leaving them uncompressed in others
- This is referred to as compression (increase in density) and rarefaction (reduction in density)
- These waves of compression need some kind of medium to travel through
-What are some mediums through which sound can travel? (air, water, sometimes solids... like when you plug your ears and talk, you can hear yourself because the sound travels through your bones)
- Because of its wave-like behavior, sound is often represented as a wave:
-Draw picture similar to this on the board. Don’t erase it yet.
-Ask students what features differentiate these waves (how often they have peaks/troughs, their height, how many peaks/troughs they have over a fixed distance)
- We can identify different features of waves
- Peak – top of wave
- Trough – bottom of wave
- Amplitude – vertical distance between crest and trough; the “height” of the wave.
- Wavelength – distance between successive high and low points. Inversely related to frequency, how many peaks/troughs move past a given point in a given amount of time. Measured in hertz (units per second)
-Of the three waves above (the colored ones on pg 2), which has the largest amplitude? (bottom one, then middle, then top)
-Largest wavelength? (also bottom, then middle, then top)
Wave activity (11:30 - 11:50 am)
-Jump rope or rope
Two students at a time will stand on either end and shake the rope to simulate waves (see picture below). By changing the speed and height of the shaking, they can change the wavelength and amplitude.
- Start by having two mentors demonstrate by grabbing opposite ends of the rope. One mentor holds the rope still while the other shakes it to create a wave.
- Have two students grab either end of the rope. One student should hold the rope still, while the other student shakes it to create a wave pattern.
- Have the group observe the movement of the rope. How regular is the motion? Do the waves all have the same or different heights?
- Tell the student who is shaking the rope (they can switch off) to shake the rope faster without moving his/her hand higher or lower. Does this affect the amplitude? Wavelength? Speed?
- Then tell the student to shake the rope slower. What’s different now?
- Get another two students and get them to start up a wave.
- Have the rope shaker move his/her hands higher and lower without changing the shaking speed.
- Have the group observe the movement of the rope. Is the amplitude different? Wavelength? Speed?
- Make sure each student gets a turn at making waves. Then, wrap-up
Shaking the rope faster should decrease the wavelength (increase the frequency) of the wave, but not affect the amplitude.
Shaking the rope with longer arm motions should not affect the wavelength but should increase the amplitude.
What is music? (11:50 am - 12:05 pm)
- Music is composed of sound, so many basic components of music are determined by physical properties of the underlying sounds#
- Pitch – how “high” or “low” a sound is
- Determined by the frequency or wavelength of the wave
- Low frequencies – make the sound powerful and warm
- Midrange frequencies – give sound its energy. Humans are most sensitive to this range.
- High frequencies – give a sound its "presence" and life like quality.
Clip of high, medium and low frequency sounds
- Loudness – how loud a sound is
- Determined by the amplitude of the wave
- High amplitudes – correspond to loud sounds
- Low amplitudes – correspond to soft sounds
Clip of gradually amplified sound. What is happening to the waveform of this sound as it gets louder?
- Other more complicated features of music are determined by many characteristics of the underlying sounds
- Harmonics – waves produced on top of a base wave, all of which combine to form an overall sound
- The overlying sounds are also called overtones
Clip of harmonics at 110 hz. First sound is base frequency and the ones after it are “part of” it.
- Timbre – the “voice” or “character” of a sound
- Determined by frequency, harmonics, and overtones
- We can tell apart different peoples’ voices, or different instruments, because of their timbres
Clip from Jason Mraz’s Lucky. Even though the male and female vocals are overlapping, you can tell them apart because of the different timbres of their voices.
- Rhythm – the timing of music
- Created by alternating strong and weak elements of sound
Clip of opening to Jay-Z’s Empire State of Mind. The rhythm is very clear from the beginning, and you can hear how it sets up the “feel” of the music even when the vocals start.
Music and Emotion (12:05 - 12:30 pm)
- There are different features of music that can change how it affects our emotions (12:05 - 12:15 pm)
Mention that a lot of this is conditioned – in different cultures, people may respond differently to the same music because these responses are largely taught.
- Tempo – speed of the music. A component of rhythm.
- Fast tempos – excitement, happiness, drama
- Slow tempos – sadness, serenity, calm
Clip of Beyoncé’s Crazy in Love and Kelly Clarkson’s Because of You, two pieces with different tempos. Do they make you feel different? Can you tell what emotions the artists were trying to evoke?
- Tonality – the relationship between sounds within the music; related to what key the music is in
- Major tonality – happiness in most Western music. Created by consonant sounds that have matching waveforms.
Clip of Olympic Theme, composed by John Williams. What emotions does the major tonality evoke?
- Minor tonality – sadness in most Western music. Created by dissonant sounds that have clashing waveforms.
Clip of Schindler’s List theme, also composed by John Williams. What emotions does the minor tonality evoke?
- Dynamic – volume or strength of music
- High dynamic (forte) – louder; intensity, power, anger
- Low dynamic (piano) – softer; tenderness, sadness, fear
Clip of Beethoven’s Symphony No. 5, an opening with lots of dynamic contrast. What emotion does Beethoven evoke through the varying loud and soft sections of this opening?
- Rhythmic regularity – how often the beat and recurring pattern of the music changes
- Inconsistent rhythm – uneasiness
- Consistent rhythm – happiness, peace
Clip of Pink Floyd’s Money, which keeps switching between a 4- and 3-feel rhythm. Compare that to, say, Justin Bieber’s Baby. Can you feel the differences in rhythmic consistency? (And general sophistication?)
- Intervals and emotion#
Mentors, only get into this if you feel comfortable explaining these concepts, have students with a basic understanding of music, and have time. Otherwise, skip it and go on to part 3.
- A note is a letter assignment of a specific pitch. Each note will thus have a certain frequency corresponding to it.
- Notes are visually represented on staffs, with each line or space corresponding to a certain note and, therefore, a certain pitch
- When two notes are played together, the resulting sound has a distinct character based on the interval between the two notes
- Intervals are one of the most important ways that music gets its emotion
- The smallest interval is the half step (also called semitone or minor second)
- Main intervals and character associated with them:
Number of half steps
Character of sound
1Minor second (m2)/half stepMost dissonant interval; very harsh, almost grating
3Minor third (m3)Sadness; makes up the minor tonality
4Major third (M4)One of the most consonant intervals; comfortable; makes up the major tonality
6Augmented fourth (A4)/tritoneMainly used interval of dissonance; unstable, awkward, uncomfortable
7Perfect fifth (P5)Neutral, stable; don’t set the mood on their own
- Music is composed of intervals, so by carefully choosing what intervals to use, musicians can control the mood of their music
- What is the human element in music that allows us to connect with it emotionally? (12:15 - 12:30 pm)
Make this a discussion. Ask students why they think music is so emotional? What do they think is the human element?
Below are possible points to bring up.
- The presence of a natural rhythm in humans (the heartbeat) suggests that, to some degree at least, response to music is in-built
- However, some aspects of music are conditioned, such as the association between a major tonality and happiness, and a minor tonality and sadness
- Another explanation: Music is interpreted as an elaborate form of speech
- Characteristics of speech that elicit certain emotions work the same way in music (e.g. fast, loud yelling excites us, just as fast, loud music does)
- And another explanation: music mimics the sound of human “expressive movements,” like stomping or running
- This could explain why even non-vocal music is emotional–if music is just an elaborate form of speech, how could it be expressive without language?
- The truth is, we don’t really know
Wrap up / Conclusion
Go over the terms in the lesson by completing the post-assessment activity.
Pre Assessment Plan
Students should discuss their favorite songs and list reasons why they believe these songs resonate with them.
Post Assessment Plan
Match the terms below:
|Audience(s)||High school students
|Activity Type(s)||Alternative Science Communication (e.g. Video, Sci-Toons, Multimedia)
|Grade Level(s)||High School
|Created||11/11/2012 02:03 PM|
|Updated||11/13/2012 11:03 PM|