How I broke a wine glass with my VOICE (using science!)

So late to the party...

Perhaps this has been mentioned already by other commenters, but I wish you had related this to other practical applications of resonance. I know your concept was narrowly defined to an untrained vocalist being able to break a glass, but at least mentioning how resonance famously caused the destruction of the Tacoma Narrows bridge in 1940, or the necessary modification of the Millennium Bridge in London after 2000. The idea that wind through a canyon or the combined movement of pedestrians can gently increase in power enough to make steel and concrete swing like rope is a pretty amazing application of resonance in our world. It reminds us even the seemingly most solid structures need to be intensely scrutinized for potential weakness that may not be inherent to the design, but rather a consequence of outside forces in the exact context of where and under what circumstances the structures are built.