A phenomenon that happens two or a few people. When a particular feeling gets more intense as the parties involved realize how intense the feelings of others is.
A Resonance is a force within everyone, comparable to a soul. It is especially strong in those who love to make and/or listen to music, fluctuating with their emotions. When your Resonance finds the right frequency, the right song, you can do more, focus harder, work faster. Whether or not that's a placebo effect is up for debate.