I too have heard this but looking at brain waves on wikipedia: Delta wave – (0.5 – 3 Hz) Theta wave – (4 – 7 Hz) Alpha wave – (7 – 15 Hz) Mu wa

I too have heard this but looking at brain waves on wikipedia: Delta wave – (0.5 – 3 Hz) Theta wave – (4 – 7 Hz) Alpha wave – (7 – 15 Hz) Mu wave – (7.5 – 12.5 Hz) SMR wave – (12.5 – 15.5 Hz) Beta wave – (15 – 30 Hz) Gamma wave – (>30 Hz) Based on the wide frequency range on any of those it's hard to justify a range as tight as 135-140BPM, "137 heaven" notwithstanding There's definitely some interesting cognitive science in what makes a good tune though. I sketched out some informal ideas here https://omnisplore.wordpress.com/2017/11/25/kolmogorov-complexity-the-thing-that-gives-energy-to-dance-music/ https://omnisplore.wordpress.com/2017/11/25/kolmogorov-compl... I used to write the odd bit of psytrance back when I had enough time in my life, hope it's not too rude to link some here :) https://oscillicraft.bandcamp.com/album/dreampsyker https://oscillicraft.bandcamp.com/album/dreampsyker