I accept that listening to certain types of music can help with some problems, such as claim that by reading his book,you'll be able to create a peaceful environment to help you relax in your home. I found the relaxation and breathing techniques very useful. Similarly,his claim that music will help you sleep better seems reasonable. I tested the "Music for sleep" section of the CD and found that after a few nights, I did indeed sleep better. However, when Fettaro goes on to promise his music therapy will help cure depression and even cancer, things start to get a little unbelievable. There is no clear evidence for any of his claims, which rely on a series of "personal success stories." I would prefer to see details of scientific research to support his assertions , and without this, I felt unable to believe many of his more extraordinary claims.