jazz, rock & the mind

in a book called the secret power of music, i have reread that jazz & rock music throw the body & mind off the rhythmic pattern & can have very negative effects on the system- as our heart, lungs, & brain all work on a rhythm. perhaps this is an insight as to why so many rock & jazz musicians use drugs to relax their minds & calm them down- perhaps the music really is messing with the harmony of the body & mind. look at jimi hendrix, janis, curt cobain, and so many other people that gave their life to music- the lifestyle got 'em. i haven't got to the part that says which music is good for the soul, but perhaps it is techo/electronica w/a steady beat, or jack johnson who just sounds like the steady flow of Hawaiian waves.