Music / Science KS2: How brass instruments make sound

In the House of Sound where the science of music and musical instruments is always being investigated, Greg Foot and Fran Scott investigate brass instruments and how they make their loud, bright sounds.

They explain that in order to make a sound, a brass player's lips must be made to vibrate very, very quickly. When placed against the mouthpiece of the instrument the air inside begins to vibrate too, forming sound waves.

To make different notes the amount of air vibrating inside the instrument has to be changed.

On a trombone, a part called the slide makes the tube of air that vibrates longer or shorter, and this changes the pitch of the note from lower to higher.

On an instrument like a trumpet, three parts called valves can be pressed down to change the amount of air.

Fran and Greg demonstrate how a sound wave travels using a large metal spring and form a standing wave with a length of rope.

Fran also demonstrates how you can easily make a simple horn from a funnel, length of hose pipe and a hosepipe connector for a mouthpiece.

This clip is from the series House of Sound.

Teacher Notes

Pupils can experiment with making sounds using just their own bodies and voices. Because sound needs a medium to travel through, they can discuss the media with which they are familiar - for example, water, a highly effective medium, as they may have discovered while swimming.

As an introduction to pitch, experiment with rulers on the edge of desks or tables, so they can find out and record that a long length of ruler vibrates more slowly than a short length and makes a lower sound.

Curriculum Notes

This clip will be relevant for teaching Science or Music in primary schools at Key Stage Two or Second Level (Scotland).

More from the series House of Sound

What is sound?
How drums make sound
How woodwind instruments make sound
How string instruments make sound