There are plenty of sites online that give instructions to make musical instruments with students. The ones featured in this video show step by step instructions, are simple to make, and use recycled materials.
Web Links
Arts and Crafts
Another site—this one with 20 DIY instruments to make.
Gutbucket
Creating a bass from scratch is a more complicated project. Many suggest the traditional wash tub but a 5-gallon bucket can work too.
Musical Glasses
This home science experiment shows how glasses filled with different amount of water will provide different sounds. By changing water levels you can create different sounds.
Idiophones
This Montessori site shows all kids of different methods of making sounds with different items that produce a sound when struck.
Summer Reading
The Collaborative Summer Library Program encourages student to build their reading and language skills throughout the summer months. Their theme this summer is Oceans of Possibilities and you can visit your local library to check out the programs in your home town.