Dusk to dawn is a particularly dangerous time because visibility is limited and motorists have greater difficulty seeing runners, cyclists, skate boarders, and roller bladers. To reduce the likelihood of accidents, a device is needed to alert motorists. A local elementary school group is planning a weekend hike during which they must carry everything, including their food and clothing. They are concerned about the heavy load each person will have to carry. Instrumental music provides us with interesting diversity. The same music played on the same instrument by different people provides us with interesting contrasts and variations in the music.