Educational Galaxy

Chapter 7: The Science of Music — EG's own notes, in simple words

Book: Madhurima (CBSE, Class 9)  |  Chapter 7  |  Section: Music  |  Medium: English

Diagram (labels are printed on the image): Vibrations from a drum and a string travelling as sound waves to the ear. A general picture about the science of sound; it is not a scene from the book.

Students watching how a string and a drum skin vibrate to make sound.

What the chapter is about

Every sound we hear begins as vibration. Something moves back and forth very fast — a string, a drum skin, the air in a flute, or our own vocal cords — and the air carries that movement to our ears. Change the vibration and you change the sound.

The human voice is a musical instrument inside our own body. We use it every day to speak, laugh, sing and shout, and various parts of the body work together to produce it. That is why this chapter treats singing as science first: once you know how sound is made, you can use your voice better and design instruments on purpose.

The three subsystems of the voice

Three main subsystems work together when we speak and sing. The air pressure system — lungs and diaphragm — pushes air out; put your hands on your belly, breathe in, and you feel it expand. The vibratory system — the larynx and vocal cords — turns that air into sound by vibrating. The resonating system — the nasal and oral cavities — shapes the sound, giving each voice its colour.

Voice care follows from this science. Speak at a moderate volume instead of shouting, and do regular vocal warm-ups: breathing and diaphragm exercises, practised five to six times each, keep the voice ready and healthy.

Instruments, beats and Konnakkol

Indian instruments are grouped by how they make sound: tata (stringed), sushira (wind), avanaddha (membranophones, like drums) and ghana (solid percussion). A string instrument can be designed from the same science: shorter, tighter or thinner strings vibrate faster and sound higher.

Rhythm is counted in beats. Jhaptāla has 10 beats (mātras) in one cycle (āvartana), and Kehervā has 8. Konnakkol, or Bol, is the art of speaking rhythm syllables — saying the beats aloud, which trains both ear and tongue before an instrument is even picked up.

What you should learn

Sound is vibration; the voice has three subsystems (air pressure, vibratory, resonating); and instruments and rhythms follow the same science.

Chart / Table: What changes a sound

Point	Detail
Faster vibration	Higher pitch
Slower vibration	Lower pitch
Stronger vibration	Louder sound
Shorter / tighter string	Higher note on a string instrument
Different resonating shape	Different voice or instrument colour
Jhaptāla / Kehervā	10 beats / 8 beats per cycle

Practice set — try it yourself

1. Feel your air pressure system: hands on belly, breathe in and out. What moves?
   Hint: Notice expansion on inhale, movement on exhale.
2. Do a daily vocal warm-up routine: breathing and diaphragm exercises, 5–6 times each.
   Hint: Stand or sit straight; inhale deeply.
3. Write a Konnakkol / Bol phrase for 8 beats.
   Hint: Speak the beats aloud in a steady pulse.
4. Name the family of each instrument: veena, flute, tabla, manjira.
   Hint: Think string, wind, membrane, solid.
5. Design a string instrument on paper using sound principles.
   Hint: Think length, thickness and tension.

Questions with Answers

1. Name the three subsystems of the human vocal system, and describe each.
   Air pressure system (lungs and diaphragm) pushes air out; vibratory system (larynx and vocal cords) turns air into sound; resonating system (nasal and oral cavities) shapes the sound's colour.
2. How can we keep our voices in good condition?
   Speak at a moderate volume instead of shouting, and do regular vocal warm-ups, including breathing and diaphragm exercises.
3. How many beats are in Jhaptāla and Kehervā?
   Jhaptāla has 10 beats (mātras) in one cycle (āvartana); Kehervā has 8.
4. What is Konnakkol?
   Konnakkol, or Bol, is speaking rhythm syllables aloud — a way to learn and feel beats before playing them.
5. What is the connection between the science of sound and musical instruments?
   Instruments are designed from vibration: what vibrates, how fast, and what shapes it decides the pitch, loudness and colour of every note.

Extension questions — go deeper

1. Fill in and justify: a shorter string sounds ___ because it vibrates ___.
   Higher, because it vibrates faster. Length, thickness and tension all change vibration speed.
2. True or false, with reason: ‘Loud singing is the best vocal warm-up.’
   False. Warm-ups are gentle breathing and diaphragm exercises; shouting strains the cords instead of preparing them.
3. Which category (tata, sushira, avanaddha, ghana) does a drum belong to, and why?
   Avanaddha: it makes sound from a stretched membrane that vibrates when struck.
4. Design a warm-up routine for a class that must sing after games period.
   Start with slow breathing, then gentle humming, then diaphragm exercises 5–6 times each — never loud shouting first.
5. If a singer's voice sounds nasal, which subsystem is shaping it most?
   The resonating system, especially the nasal cavity, which colours the sound after the cords vibrate.

How to use this page: Read the summary, say the Key Terms in your own words, then try the practice set without looking. Use the Questions with Answers to check yourself afterwards. Ask your teacher or parent to check your answers.