The Opera Diva, the Catalyst, and the Big Smash

Some of you might have heard or read about the tale of the opera singer who could really sing in tune and did so extremely well. Once she decided to try to approach the tone quality of the clink of a glass object on her table when that object was gently struck. It seemed that she succeeded, and her voice turned stronger and stronger and ----smash! --suddenly the glass object was split to pieces. The two vibration systems (the singer and the glass structure) were in harmony, as a musician would say, they were in resonance, a physicist would say.