Sophie Duncan investigates the sound of music
The Science Museum in London houses a special record player - it plays chocolate records. This makes it ideal when music fashions change so quickly, as it is good fun disposing of your old records.
If you have a record player, and a record that you don't mind damaging, you can explore the principle behind a loud speaker. Take a plastic cup and push a pin through the bottom, so that the top of the pin is on the inside of the cup. Secure the top of the pin with sticky tape.
Start the turntable, making sure you have disabled the needle. Lightly rest your pin in the groove on the record, and place your hand over the top of the cup. You should be able to hear the music, as the cup amplifies the sound. If you are too modern to have your own record player, The Little Book of Experiments has the answer - the clucking cup.
To make a clucking cup, you need a plastic cup, a piece of string and a damp cloth. Fix one end of the string into the inside of the cup with a piece of sticky tape, and turn the cup upside down so that the string hangs down. Rub the string with the damp cloth, using small jerky movements. With a bit of practice you should be able to make the cup cluck. To make other farmyard noises use different sizes of cup - you could even use a dustbin, which should give you a deep sound similar to a cow mooing.
The Little Book of Experiments has been sent free to primary schools in the UK, and can also be accessed online at www.planet-science.com
Sophie Duncan is project manager for science at the BBC www.bbc.co.ukscience