A similar notion exists in the field of group analytics, which actually refers to group psychoanalysis. This psychological school of thought and practice, created out of the work of S.H. Foulkes (with the participation of the renowned sociologist Norbert Elias, among others), aims at exploring the social unconscious of the group so that the analyst can help them with their personal challenges. Practitioners of this approach also use the expression “resonance” to explain how to access this intangible social unconscious. For group analytics to work, all the participants must “resonate” together to find out what negative and destructive socially shared beliefs or views is alienating them. The same process can be used to have them embrace other socially shared beliefs or views that are much more positive and progressive. For instance, moving from notions like “all alcoholics are losers” to “a survivor’s resilience is the mark of true greatness”. From such a concrete and empirical perspective, the notion of which reality becomes the “truer” one can be described as a matter of adjusting to different harmonics.
In the larger scale social realm, this process is called the “social construction of reality” and can be seen as a matter of harmonics too. What is important, meaningful, acceptable, and ultimately “real” is matter of collective consensus in societies. Such consensus changes over time, but it is not necessarily easy (like in group analytics). A clear example is the change from a relatively conservative Western world from the time of WWII to a relatively liberal one by the late 1960s was clearly chaotic. Changes of such a depth are rare, and a lot thing must resonate together for such changes to occur (a lot of youth socialized the same way (i.e. the baby boomers), a favourable economic climate not interfering with other issues, a recent past that calls for some serious changes (i.e. the Holocaust), etc.). The very quick end of communism in the Eastern bloc can also be described as a period where there was many social realities resonating together (e.g., even leaders of communist parties agreed that it was time for major social changes).
In the world of parapsychology, it is also possible to extend the notion of resonance to group experiments. The landmark studies conducted by Kenneth Batcheldor and Owen & Sparrow (the famous Philip Experiment) show that to have group psi effects everyone has to be mentally and emotionally on the same page. This very notion of resonance as descriptor of social dynamics might be applicable to larger groups as well, as the experiences conducted by the Global Consciousness Projects might have shown. Their best case is certainly the higher degree of synchronization of about 20 Random Number Generators (RNG) scattered around the globe a few hours before 9/11. Ultimately, this raises the question to whether large scale paranormal events might not be the product of larger communities unconsciously resonating as a collective.
Notions like resonance and harmonics remain, of course, metaphors, or more appropriately explanatory structures. They are not reality itself but representations of realities. Yet, as we used them they become reality, a reality that is much more interesting to contemplate as it offers new and promising avenues of investigation.