Topic: Playing the guitar

Supplementary material for use in lessons in the group of natural sciences (nature, biology, chemistry, geography, physics), additional classes, science clubs. It can serve as a resource for expanding knowledge, preparing students for science competitions.

Target group:

8th‑grade students of elementary school (physics).

Core curriculum

8th grade of elementary school – physics

VIII. Vibrating motion and waves. Student:

7) qualitatively describes the relationship between sound pitch and wave frequency and the relationship between sound intensity (loudness) and wave energy and wave amplitude;

8) distinguishes audible sounds, ultrasounds and infrasound; lists examples of their sources and applications;

9) experimentally:

b) demonstrates sounds of different frequencies using a vibrating object or musical instrument.

General aim of education

Students experimentally examine the dependence of the sound produced on the stress and length of the string.

Key competences

• communication in foreign languages;

• digital competence;

• learning to learn.

Criteria for success
The student will learn:

• to describe how a musical instrument produces sound;

• explain what affects the pitch of the sound;

• to explain how the length and tthe ension of a string affects the pitch.

Methods/techniques

• activating

  • discussion.

• expository

  • talk.

• exposing

  • film.

• programmed

  • with computer;

  • with e‑textbook.

• practical

  • exercices concerned.

Forms of work

• individual activity;

• activity in pairs;

• activity in groups;

• collective activity.

Teaching aids

• e‑textbook;

• notebook and crayons/felt‑tip pens;

• interactive whiteboard, tablets/computers;

• a guitar made by myself;

• cards from the technical unit.

Lesson plan overview

Before classes

• The students make the guitar themselves from publicly available materials according to any instructions found on the Internet.

Introduction

• The teacher explains the aim of the lesson and together with students determines the success criteria to be achieved.

Realization

• The instructor asks the pupils to examine the conditions that must be met in order for the sound of the strings they created to be: high / low; loud / quiet.

• Students compare their observations made during their research with the information contained in the abstract.

• The teacher announces a movie. He instructs his pupils to write a research question and a hypothesis in the form provided in the abstract. Then he plays the video and the students note their observations and conclusions. The teacher points the person who shares his insights and explains the reasonableness of the conclusions noted.

• The teacher stops the film at selected moments and instructs the pupils to specify the type of sounds they hear.

• Students independently perform interactive exercises No. 1 and No. 2.

• The teacher displays the illustration of „The volume of sounds issued by some items” and explains what decibels are and which sounds are dangerous to human health.

• The lecturer asks students how they have heard the echo. Then, students wonder what use this phenomenon may have.

• The teacher explains the concept of echolocation and asks those under their care who are familiar with animals using the echo effect for orientation in the environment.

• Students, working in pairs, conduct „Observation 2”. They explain when they heard the sounds better: by putting a tube of technical sheets on their ears or without them. They give examples of animals that have large ears and explain the relationship between the size of the ears and the functions they perform.

Summary

• Students independently perform interactive exercise No. 3.

The following terms and recordings will be used during this lesson

Terms

Texts and recordings

Playing the guitar

Whenever you’re playing a musical instrument, you make particles in its immediate vicinity vibrate. How is it that an instrument can produce both high and low tones? What affects pitch? Lets examine it by conducting an experiment.

The faster the body vibrates, the higher sounds it produces. If you take a look at a guitarist playing their instrument, you’ll be able to see that they press strings in such a way so that only parts of them vibrate. This way, the speed (frequency) of vibrations changes. The more vibrations per second, the higher the sound. Average human ear is able to hear sounds with a frequency from 20 to approx. 20,000 vibrations per second. Higher sounds are called ultrasounds.

Pitch depends on the frequency with which the source vibrates. On the other hand, whether sound is loud or soft depends on the strength of vibrations. For instance, the harder you pull on a guitar string, the stronger the vibration (the greater the amplitude of vibrations) and the louder the sound produced. This will not cause a change in pitch.
The larger the distance from the source of sound, the more it will lose its intensity. Vibrations are reduced until they finally disappear. Sound volume is measured in decibels (dB). Sounds louder than 130 dB can cause ear pair and even permanently damage your hearing.

If the guitarist that you’re observing gives a concert at a large hall, you may hear an echo. Where does it come from? Sounds can reflect from large surfaces, e.g. walls, mountain slopes or a dense forest wall. Sound reflected from an obstacle is called an echo. Certain animals can use this phenomenon to orient themselves in their surroundings.

All instruments are build so that they produce sounds audible to humans. However, certain bodies vibrate with such frequency that they’re not audible. Although for humans hearing plays an extremely important role, it’s not the most vital of the senses. For many animals it’s different. For instance, for nocturnal animals hearing provides the most information about their surroundings. Some animals have large auricles and the ability to move them. In your opinion, how does that help them?

Owing to large and mobile auricles, animals hear softer sounds. That’s why many herbivores has good hearing – they’re able to hear a predator sneaking up on them before they see it and run away.

• Pitch depends on the frequency of vibrations. The more frequently the object vibrates, the higher the sound it produces.

• Sound volume depends on the amplitude of vibrations of the body being its source.

• Humans are able to hear sounds with a frequency from 20 to approx. 20,000 vibrations per second.