I was raised on a farm, and in my youth I dug enough fence post holes to last a dozen lifetimes. My father used to joke that he gave me that chore so that I’d have lots of practice and get good at digging fence post holes. From a pragmatic point of view, the purpose of digging all those post holes was really not so that I’d become a better post hole digger, but so that I could plant posts in them. Once you dig a post hole to the correct depth you don’t keep on digging, trying to make the hole fancier or more aesthetically pleasing. You stick a post in that sucker, tamp the earth back in around it so that the post is secure, and then move on to dig the next hole.
The composer Alvin Lucier has written many pieces that feature interference beats as their main focus. Italian composer Giacinto Scelsi, whose style is grounded on microtonal oscillations of unisons, extensively explored the textural effects of interference beats, particularly in his late works such as the violin solos Xnoybis (1964) and L'âme ailée / L'âme ouverte (1973), which feature them prominently (note that Scelsi treated and notated each string of the instrument as a separate part, so that his violin solos are effectively quartets of one-strings, where different strings of the violin may be simultaneously playing the same note with microtonal shifts, so that the interference patterns are generated). Composer Phill Niblock's music is entirely based on beating caused by microtonal differences.
Both brainwave entrainment and neurofeedback deal with brainwaves, but the similarity stops there. Entrainment pushes your whole brain into a pre-determined state, while neurofeedback teaches you how to move specific parts of your brain on your own. It is the differeence between forcing the brain into a given position, and skills building so you can move it there yourself.