This unit is "Musical Instruments" by School Express. You can sign up for School Express's newsletter to get a new free unit study each Sunday. See http://www.schoolexpress.com/.
My daughter did the unit study on her own, designed her own lapbook, and presented it to the class.
Once your kids get comfortable with lapbooking, challenge them to design some of their own. This is a great learning activity that is fun to do!
Happy lapbooking! :-)