 The stress-reducing effects of music appear to extend throughout the clinical spectrum, even to the critically ill, intubated, and intensive care unit. Those with headphones on their head playing Mozart cut stress hormones like adrenaline in half compared to those with headphones playing nothing, resulting in a lower mean arterial blood pressure. But are all types of music just as relaxing? Researchers compare the effects of Mozart versus Pearl Jam versus Enya on normal, healthy subjects. What do you think they found? After listening to Mozart for 15 minutes, people reported a significant reduction in tension with new age music. They also got a reduction in tension, more relaxation, less hostility, but reports of a significant reduction in mental clarity and vigor. And after Grunge Rock, people said they felt more hostile, tired, sad, and tense, with reductions in caring, relaxation, clarity, and vigor. But these were just subjective measures, asking people how they felt. What about objective measures? Well, we do have data on techno. After 30 minutes of classical music, the stress hormone cortisol significantly dropped. But if instead of listening to Beethoven's Symphony No. 6, opera 68, they listened to Cybertrip's Techno Shock, Techno Magnetico, stress hormone levels went up. Now, endorphin levels went up too, which you may think, oh, that's nice, until you realize that endorphins are our body's natural painkillers and go up after a variety of aversive stimuli, like getting burned or prodded. This may just be a function of the tempo, though. People get the same bump in breathing and blood pressure listening to fast classical music of Vivaldi's Presto, as stimulating even more so than the Red Hot Chili Peppers. What about heavy metal music? Participants were randomly assigned to self-selected classical heavy metal or silence. Listening to self-selected and classical music produced increased feelings of relaxation, as well as sitting in silence, but not so much for the heavy metal condition. Compared to relaxing and pleasant renaissance music, exposure to arousing an unpleasant heavy metal caused a heightened amylase response in men. Amylase is an enzyme in our saliva that digests starch. And so when we go into fighter flight mode, we can immediately start churning out the enzyme to provide sugars for quick energy. So you get a spike when you go skydiving, or if someone dunks you in near-freezing water, or if you make a guy listen to heavy metal for 10 minutes. With all that extra enzyme, if he's eating bread while banging his head, he could end up digesting it better. Metal is more likely to cause the medical community indigestion, though. Although the American Medical Association's Group on Science and Technology admits there's no evidence that this music has any deleterious effect on the behavior of adolescents, that doesn't stop them from suggesting this anecdotal evidence that those who identify with such blunt bands as slayer and metallica may be at risk for drug abuse, or even participation in satanic activities. To which one doctor wrote in to reply that for every teenager who commits suicide or some crime under the influence of heavy metal music, there may be dozens of white-collar criminals engaged in such activities as insider trading, fraud, and corruption. Maybe we should instead be blaming Bach or Barry Manilow.