Sound Travels #7 - Pitch

Measuring with Unifix Cubes

Yesterday the children collected some data from the guitar they made and tried to figure out why the strings make different sounds. First, they used Unfix cubes as a measurement to measure the length of each elastic band stretched across the guitar. Then they plucked each band to see if it made
a high sound or a low sound. After we organized all the data, we found that the longest elastic band made the highest sound and the shortest elastic band made the lowest sound. I explained to the children that the high and low of a sound is called the pitch. When the elastic band is stretched, it will create a faster moving sound wave and a higher pitch. When the elastic band is not stretched as much, the sound waves move slower and produces a lower pitch.

Selecting a tone bar

Using what we know about pitches, the children each picked a tone bar and compared it with each other. They noticed some bars have high pitches and some have lower ones. As they played their notes, Theo said that it sounded like a song. So we put our tone bars together and each child took turn playing the tune. When it was Molly's turn, she played the song with a rhythm. This inspired the other children to create their own rhythms too.