What is brainwave entrainment and what does it have to do with sound meditation?

Tonight I had a vision at the end of a short sound meditation practice. I used to have visions a lot at the beginning of the pandemic during gong journeys, but it had been a bit. I was completely cognizant, so this was kind of a day dream. There were three mini versions of me, childlike, maybe even children, in red silly costumes dancing together in a row and creating a show. Have fun! Is the message I got. You take yourself too seriously.

 Another interpretation of this vision could be that those costumes were joker costumes and I'm working too hard to get attention. Hm.....

With all interpretations and joking aside (we'll discuss interpretation at a later date), WHY do many people have the propensity to get insight, creative inspiration, and visions during or after listening to overtone-emitting instruments, for me especially the gong?

With my knowledge of brainwaves, it seems clear that I went into a theta state: the brainwaves dominant during dream sleep, creative outpouring, and deep meditation. But how did I do that with only a 15 minute gong meditation, when it takes some people years of practice to access deep meditation?

The magic of brainwave entrainment is one of my favorite scientific studies behind sound meditation. Have you ever seen a video of metronomes all ticking separately, and then magically they begin to tic together? (see video below) This is a phenomena called systems theory, also seen in the alignment of collective bird movement. It illustrates how biological and physical systems naturally tend to synchronize their periodicity and rhythm through interraction. Brainwave entrainment is the related phenomena in which our brainwaves align naturally with external aural or visual stimulae, in the form of pitch, rhythm or flashing lights. THIS is the phenomena that happens when listening to overtone-emitting instruments like the gong, and the reason why we can get to these lower brainwave states so easily and naturally.

But wait, there's a hitch! This entrainment can be positive or negative, depending on whether the stimuli is helpful or not for the body functioning! If one is epileptic, for example, it is negative entrainment if flashing lights bring on a seizure. But if listening to overtone instruments naturally can bring us to deeper states of meditation, access our center of intuition and creativity, connect to our subconscious dream states while still cognizant (and also therefore accessing ability to reprogram unhelpful habits) without needing to meditate every day for 40 years for 10 hours a day.... COUNT ME IN!!!