Class 9 · ArtsNCERT 2026 Revised Syllabus
Chapter 7: The Science of Music (0907AR07)
Madhurima
Links the science of sound to music — how pitch, loudness and tone quality work, the human vocal system, and rhythm through mathematics and tala.
Chapter code: 0907ar07 · Book: Madhurima · Class 9 Arts
Find complete NCERT solutions for Class 9 Arts, Madhurima Chapter 7. Every question has a clear, step-by-step answer for chapter code 0907AR07.
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Section A - The Science of Sound(10 questions)
1
What do you hear when you hold the rubber band between your fingers and strum it?
Ans.
A very faint, weak sound is heard, since the vibrating band has no surface to amplify it.
2
What happens to the loudness when the rubber band is stretched across the hollow box and plucked?
Ans.
The loudness increases, as the hollow box resonates and amplifies the vibrations of the band.
3
What happens to the pitch when the band is stretched tighter and plucked again -- does it become higher or lower?
Ans.
The pitch becomes higher, because a tighter string vibrates at a faster rate (higher frequency).
4
How does the sound change when rubber bands of different thickness are used?
Ans.
The sound quality (tone/timbre) changes with the thickness of the vibrating band; the textbook treats thickness/material as affecting the quality of sound.
5
How does the sound change when the rubber band is replaced with a piece of string or thread?
Ans.
The tone quality (timbre) changes -- the string produces a clearer, sharper sound than the rubber band, since the material of the vibrating object affects the quality of sound.
6
Observe that the instrument has a hollow body. How does this enhance the sound?
Ans.
The hollow body acts as a resonating chamber that amplifies the vibrations of the string, making the sound louder and fuller.
7
When the strings are tightened, the pitch -- (increases/decreases/stays the same)?
Ans.
Increases (the pitch becomes higher).
8
When the strings are loosened, the pitch -- (increases/decreases/stays the same)?
Ans.
Decreases (the pitch becomes lower).
9
How does the thickness of the string affect the sound?
Ans.
Changing the thickness of the string changes the quality (tone/timbre) of the sound; the textbook specifically describes thickness/material as affecting sound quality.
10
Describe the tone of a note played on the instrument -- is it short or sustained? Is it high-pitched or low-pitched?
Ans.
This depends on the instrument used in class and the note played. Describe whether the note is short or sustained and whether it is high- or low-pitched, based on your actual observation.
Section B - Mathematics in Tāla(6 questions)
1
Write a rhythmic phrase (bol) for 7 akharas.
Ans.
4 + 3 = tha ka di mi ta kita.
2
Write a rhythmic phrase (bol) for 8 akharas.
Ans.
4 + 4 = tha ka di mi tha ka di mi.
3
Write a rhythmic phrase (bol) for 9 akharas.
Ans.
3 + 3 + 3 = ta kita ta kita ta kita.
4
After how many cycles will Group 1 (reciting the 3-beat phrase) and Group 2 (reciting the 4-beat phrase) clap together?
Ans.
After the 12th beat -- the Lowest Common Multiple of 3 and 4 is 12. By then, Group 1 completes 4 cycles of 3 beats and Group 2 completes 3 cycles of 4 beats, so both say `ta' and clap together.
5
The LCM of 12 (Ektala) and 16 (Teental) is ___.
Ans.
48.
6
After ___ beats, both tālas would have completed full cycles.
Ans.
48 beats -- Teental completes 3 full cycles (16 × 3) and Ektala completes 4 full cycles (12 × 4).
Exercises(10 questions)
Q1
Fill in the blanks: (i) When a string is tightened, the pitch ______. (ii) The diaphragm and lungs form part of the ______ subsystem. (iii) The hollow body of a musical instrument is important because ______.
Ans.
• When a string is tightened, the pitch increases (becomes higher).
• The diaphragm and lungs form part of the Air Pressure subsystem.
• The hollow body of a musical instrument is important because it resonates and amplifies the sound, increasing its loudness.
Q2
State whether the following statements are True or False: (i) The thickness of a string affects the quality of sound. (ii) Drinking water is bad for the voice. (iii) C.V. Raman conducted experiments on the sound of the veena.
Ans.
• The thickness of a string affects the quality of sound. -- True.
• Drinking water is bad for the voice. -- False (drinking water keeps vocal cords hydrated and helps them vibrate efficiently).
• C.V. Raman conducted experiments on the sound of the veena. -- False (Raman experimented on the mridangam and the tabla).
Q3
Name the three subsystems of the human vocal system, and describe the function of each.
Ans.
The three subsystems are:
• Air Pressure System (diaphragm, lungs, surrounding muscles) -- supplies the breath that powers the voice.
• Vibratory System (larynx/voice box and vocal cords) -- vibrates to produce musical sound .
• Resonating System (throat, mouth, nasal cavities) -- shapes and amplifies the vibrations into distinct vowel tones.
Q4
Describe some ways to ensure our voices are in good condition.
Ans.
Drink sufficient water to keep the vocal cords hydrated; eat a healthy diet and avoid oily or acidic food; speak at a moderate volume; and do regular vocal warm-ups to prevent fatigue.
Q5
Jhaptala has 10 beats (mātrās) in a cycle, and Keherwa Tāla has 8 beats. After how many beats will they both complete full cycles together?
Ans.
The LCM of 10 and 8 is 40. Both tālas will complete full cycles together after 40 beats -- Jhaptala completes 4 cycles and Keherwa completes 5 cycles.
Q6
Describe a warm-up routine that can be done daily to keep the voice in good condition.
Ans.
A daily vocal warm-up routine (each exercise practised 5–6 times) includes:
• Breathing and Diaphragm Exercise -- deep inhalation, holding, and slow exhalation to activate breath control.
• Humming (Bhramari pranayama) -- humming while sliding pitch up and down to warm up the cords and improve resonance.
• Lip Trills/Bubbles -- blowing air through closed lips to relax facial muscles and improve airflow.
• Sargam Exercises -- singing alankara patterns at varying speeds to improve flexibility and breath control.
Q7
Write a Konnakkol/Bol phrase for: (i) 5 akharas (ii) 6 akharas.
Ans.
• 5 akharas: 2 + 3 = taka takita.
• 6 akharas: 3 + 3 = takita takita (or 2 + 2 + 2 = taka taka taka).
Q8
Describe the connection between the science of sound and musical instruments (in about 50 words).
Ans.
Musical instruments work on the scientific principles of vibration: tightening or loosening a string changes its pitch, a hollow resonating body increases loudness, and the thickness or material of the vibrating part determines tone quality. These same principles govern how every instrument is designed and played.
Q9
If you were to design a string instrument using the principles of sound, how would it look and sound? (Diagram description)
Ans.
Design description: A string instrument with the following labelled parts, based on the science of sound learnt in this chapter:
• A hollow wooden resonator box -- to amplify the sound (loudness).
• A long neck fitted with tuning pegs -- to tighten or loosen the strings and control pitch.
• Several strings of different thickness/material, chosen to provide the desired tone quality.
• A bridge over the resonator -- to transmit string vibrations to the hollow body for a richer, sustained tone.
(Draw and label these parts -- resonator box, neck, tuning pegs, strings of varying thickness, and bridge -- on a simple outline sketch.)
Q10
Which category of instrument (tata, sushira, avanaddha, ghana) does the human voice belong to? Justify your answer.
Ans.
The human voice is closest to the tata (string) category. The vocal cords act as the vibrating source, like a string; the lungs and diaphragm provide the driving force, like bowing or plucking; and the throat, mouth and nasal cavities resonate the sound, like the hollow body of a stringed instrument.
Activities — How to Do(1 questions)
1
Activity 7.3 (experiencing the vocal system): feel the belly move on breathing; add a soft mmmm on exhaling; then shape mmmm into aaaa, oooo, eeee, uuuuu. What three systems are you feeling?
Ans.
Hand on belly: expansion shows the air-pressure system (diaphragm, lungs). Adding mmmm links breath to the vibratory system (larynx, vocal folds). Shaping vowels shows the resonating system (throat, mouth, nasal cavities) colouring the tone.