Dianna Cowern, who publishes as Physics Girl, made this four-minute video in 2014. It uses a Chladni plate as the centrepiece but keeps returning to the same question: how is this like a guitar string, or a wine glass that sings when you rub the rim?
The answer is standing waves, and the video leans on borrowed animations (a slinky standing wave from Penn State Schuylkill, a reflection simulation by Walter Fendt) to show what a node and antinode are before applying the idea to a plate. That ordering helps: once you have seen nodes on a string, nodal lines on a plate stop looking mysterious.
It is pitched at a general audience and does not go into plate geometry or material. As an entry point for someone who has never met the word resonance it is one of the better ones.