Holosync CD's (mp3's now?) can be found at Centerpointe Institute. www.centerpointe.com. Bill Harris of Centerpointe is the person who developed Holosync.
Ten years ago I bought Centerpointe's Holosync CD's. You start at a low level and work up to higher and higher levels. The method used is brain entrainment, caused by different pitches of tones. The tones are covered by music and you can not hear the tones. They promise meditation at an advanced rate, much faster then transcendental meditation. Centerpointe offers support for the program and you can email or phone them at any time.
I made it to the 3rd level and then quit the program. I was not getting the results that I had hoped for. But that is just me. Everyone is different.