membranophones, which add timbre to the sound of being struck, (this includes the entire family of drums)
idiophones, (made of such material such as wood, metal, or bone, examples are Bells, Gongs, Triangles, Marimbas, and wood blocks) which make a pitched sound by themselves.
Just sing at a comfortable pitch and try to sing a bit softer. Don't try to sing to loudly or out of your singing range (too high or too low). You should warm up your voice before you start singing by doing some gentle vocal exercises.