Music and science

01 Sound is a wave

Sound begins with a vibration that travels through a medium (air, water or solids) in the form of a wave. Sound cannot travel through a vacuum.

• Frequency (Hz) → pitch: high or low sounds
• Amplitude (dB) → loudness: loud or soft
• Waveform → timbre: the «colour» of a sound
• In air, sound travels at about 340 metres per second

Activity: Stretch an elastic band and pluck it: the tighter it is, the higher the sound.

02 Pythagoras and the mathematics of intervals

Using the monochord, Pythagoras discovered that dividing a string in simple ratios produces consonant sounds.

• 1:2 → octave
• 2:3 → fifth
• 3:4 → fourth
• Note values are fractions: semibreve = 2 minims = 4 crotchets

Activity: Calculate how many quavers are needed to fill a bar in 4/4.

03 The ear and the brain

The ear turns vibrations into nerve impulses through the outer ear, eardrum, tiny bones (hammer, anvil and stirrup) and cochlea. The brain then recognises melodies, rhythms and emotions.

• The human ear can hear roughly from 20 to 20,000 Hz
• Prolonged exposure to sound above 85 dB can damage hearing
• Making music trains memory, attention and coordination

Activity: Use a sound level meter app to measure the noise in the classroom during break time.

04 Animals and the sounds of nature

Many animals communicate through sound: birdsong, whale calls, and the ultrasonic sounds of bats and dolphins.

Activity: Record three sounds from nature and describe their pitch, loudness and timbre.

05 Technology and sound

From Edison's phonograph (1877) to streaming: science has changed the way we record, produce and listen to music.

• Phonograph, gramophone, record, magnetic tape
• Synthesiser and electronic music
• Digital sound: sound turned into numbers