Teach sound with resonance

I have been thoroughly enjoying working on an all encompassing Sound Unit and am enjoying creating an interactive powerpoint presentation to introduce the concepts of what sound is and how it travels to students.
I have a lot of fun trying to find activities to really engage students from the get go and try to integrate lots of practical activities for students as well as embedding videos.
One of my favourite sound videos for kids is this sound resonance video in which a metal pad is connected to a sound wave generator. Sprinkle some salt on top and turn up the voume.
The various frequencies create waves of varying amplitude and wavelength, which in turn vibrates the metal plate in different ways.
The resulting changes in patterns created by the salt are absolutely beautiful to watch and can be inspiration for other student art lessons.
Take a look at this awesome video.