A marimba is a musical instrument consisting of a set of graduated wooden bars (often with resonators beneath to reinforce the sounds) which is struck with mallets. A xylophone is a musical instrument consisting of a graduated serires of wooden bars, usally sounded by striking with small wooden hammers.
A gong can be made from any object that makes a pleasing sound when suspended freely and struck with another object. Both the gong and the striker contribute to the sound. Most of us think of gongs as flat, and, indeed, the metal top from a large can (such as a paint can), makes a great gong, but other interesting sounds can be obtained from more unusually shaped objects.
Try going to a junkyard and appropriating some autoparts. Automobile coil springs and brake drums are some possibilities. Other parts might make good beaters. Cover with paint, drill some holes if necessary, and hang from some wire, chain, or heavy cord and you've got a gong like no one else's!
Another easy-to-make rhythm instrument is the tambourine. All you need is a small piece of wood (in a size that's easy to grasp), some bottle caps (the kindyou have to take off with a bottle opener, not thetwist-off kind), and a hammer and nails. Turn eachbottle cap and hammer into the block of wood, butdon't hammer the nail all the way in; leave a gap. Putabout four or five bottle caps on, then shake. Kids candecorate however they like.
Take a trip to the music store. Try out different drums and other percussion instruments. Notice their construction and talk about the differences in their sound and feel. Examine instruments from other cultures. You can also listen to recordings of music that feature unusual percussion instruments. Those of the Paul Winter Consort come to mind, but there are many others. Ask the clerk at your local musc store for suggestions.
The marimba (basically, a xylophone) is another instrument you can strike to make music. With the marimba, however, you can construct a series of notes by varying the length of the bars.
You can make a no-fuss marimba by finding wood that has a nice sound (hardwoods usually have the best tone), cutting it into pieces of different lengths, drilling holes through the top and bottom of each piece, running cords through each piece, and suspending both ends between two poles. A beater stick can be made from a wood dowel with a wood ball or large wooden bead on the end (these can be purchased already turned or milled at a factory and sold as finished pieces).
You can experiment by placing the bars in an approximate scale, or simply placing them at random in any pleasing tone arrangement. The placement of the drilled holes will alter the sound, so you'll need to experiment with that as well. Bars can also be attached to two cross pieces or risers, which are best made of a less-hard wood such as pine.
Another instrument to make that's struck, but in a much more delicate way, is a set of water-glass chimes. You can try using different glasses, or a set of the same glasses that are filled with different amounts of water. Use teaspoons to strike the glasses. Experiment until you have an eight-note scale, then play a melody.
Smaller children might have a problem being delicate enough with water-glass chimes, but older children are fascinated by them. You may end up collecting odd glasses at yard sales to let your kids make their own water-glass chimes when the spirit strikes them.
They may even want to form their own "bell" chorus, complete with harmony (produced by striking two or more glasses at once). Remember, the lighter and more gentle the tap, the clearer and more sparkling the sound.