Before we can learn about music, we must first learn about sound. But diving into the world of sound opens up an array of disciplines that would take a long time to cover: physics, fluid dynamics, anatomy, psychology, and a bit of philosophy. To save you some time, we put together this short cheat sheet on the basics of sound using songs and music. We pose some thought provoking questions at the end that will entertain but also challenge your students. Many of the concepts and examples listed below come from the book This is Your Brain on Music. If you like this topic, we highly recommend this book.
The Basics
Humans can perceive sound between the frequencies of 20 Hz and 20,000 Hz. Listen here:
A pipe organ can produce sounds at the low end of about 30 Hz and a piccolo at the high end of about 12.5 kHz. Here are some songs that use sound frequencies at both extremes:
- Low Frequency Sounds
- A Day in the Life, The Beatles – the chord at the very end is ~15Hz
- In Da Club, 50 Cent – the bass beat is ~20 Hz
- High Frequency Sounds
- 2003 Mariah Carey Star spangled banner – At the end she hits a G7, ~3k Hz
- Stars and Stripes Piccolo – ~3k Hz
All sound is just vibrating air molecules, called sound waves, that interact with our eardrums. Generic noise is a random sound waves that don’t have a repeatable pattern. Notes, or what we all a pitch, is a sound wave with a repeatable pattern. This video explains the different between noise and notes.
Octaves
Most humans perceive octave jumps (doubling or halving of the frequency) as similar notes. Here is a quick overview on note octaves.
Here are some songs with octave jumps:
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Somewhere Over the Rainbow, Judy Garland
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Star Man, David Bowie
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My Heart Will Go On, Celine Dion
Major and Minor Keys
Songs in major keys feel happy and light. Songs in minor keys feel sad and dark. We don’t really know why. Here is a short example of major vs minor.
Here is Don’t Worry, Be Happy in both keys:
- Major (original): https://www.youtube.com/watch?v=L3HQMbQAWRc
- Minor: https://www.youtube.com/watch?v=LbTxfN8d2CI&feature=youtu.be
- Jolene by Dolly Parton switches between minor and major keys. Learn to play Jolene here.
Instruments & Overtones
Why do instruments sound different? The reason the same note/pitch/frequency sounds different between different instruments is because of Timbre, or the amplitude of overtones.
Tempo
Tempo is the speed at which music moves. Basically how fast you are tapping your foot. However, two songs can have the same tempo but feel very different. Both of these song are played at 96 beats per minute (bpm):
Thought Provoking Questions for Students
- If we play a song in different keys and at different volumes, we recognize it as the same song. Why is this? The sound is totally different but we hear it as the same song.
- Some sounds (like descending melodies or minor keys) appear sad and some appear happy (ascending melodies major keys)…why?
- If a tree falls in the forest and no one is there, does it make a sound?
- Why does ‘out of tune’ notes sound bad to us? What exactly makes them bad?
- Why do doubling or halving frequencies (octave jumps) sound similar? If I double the temperature in a room, it doesn’t feel similar. If I double the amount of water in a bucket, it doesn’t look similar.
- Why does this certain arrangement of sounds we call “music” sound pleasing to us? Why does it make us dance? My dog doesn’t dance. Does a certain set of sounds make other species dance? (Hint: birds)