In replaying old tapes in my head and sorting through the musty corners of my brain (long hair mostly since the 60s, not much light gets in), for entrainment and related stuff. Lozanov did a lot of work summed up in "Superlearning". Working in Bulgaria, with a limited selection of music, found best results with largo movements of baroque music. Since, some folk say good results also with certain "New Age" music, if it beats at about 60 beats/min. Robert Monroe, he of the Monroe Institute, uses a technology similar to ting-shas, preferably with headphones so the sound is inside your head. Monroe calls his process"Hemi-Sync", a nod to its demonstrated ability to synchronize the halves of the brain. Master Charles, who sells stuff he says will have you meditating like a monk in no time, uses a process I believe is quite similar, but his term for it has not surfaced in my head. Apparently my brain is not sufficiently synchronized. A company called, I think, Holistic Programs is working with binaural technology where the hz of the two tones is harmonically related, which they say enhances the entrainment. I've not had the chance to test-drive it.

That's further directions for inquiry, and those may lead to others.