The experiment setups varied. In one, Dunbar's group tested whether people who had been to a charismatic church service, with lots of communal singing, clapping and upper-body movement, had greater post-church pain tolerance than people who had been to a more placid Anglican prayer meeting. In another, they tested whether people who had been playing in a drum circle had greater pain tolerance than people who had passively listened to music or watched an instructional video. In a third, they compared pain tolerance between people who had been dancing and people who had been rehearsing music, and they frequently interrupted the musicians in the hope that the musicians wouldn't be able to achieve flow.

In all the experiments, the active groups -- the singing churchgoers, the drummers, the dancers -- had significantly greater pain tolerance than the more passive groups. Performing music, Dunbar said, released endorphins, which are associated not only with greater pain tolerance. "Psychologically, endorphin release is experienced as a mild opiate 'high,' a corresponding feeling of well-being, and light analgesia," he wrote.

Gibbard, who runs 40 to 50 miles a week and has finished two marathons, say the research makes sense to him. "When I finish playing a show, I feel the same as after a long run," he says. "As a runner, the only thing that gives me the same feeling is playing live."

Although Dunbar's experiments involved elemental forms of music performance, he said his findings extend to playing other instruments. "Blowing, as in wind instruments, requires very tight control of the chest muscles to maintain air flow from the lungs and this is tiring," he said. "Likewise, playing a stringed instrument requires fine motor control and will be tiring."

The key, Dunbar said, is the physical performance of the music, which is why in one of his experiments the drummers had greater pain tolerance than the people who had sat passively listening to music. So while listening to music might bring you all sorts of pleasure, unless you dance your way through your next Death Cab for Cutie concert, chances are Gibbard will feel better after the show than you do.

If you're inspired to dig out your old instrument in the hope of bettering your mood, bear in mind that Dunbar's findings pertain to performing, not rehearsing music. "It is probably the uninhibited flow or continuity of action that is important: if the music is frequently interrupted (as in rehearsals), any effect is markedly reduced (if not obliterated)," he writes.

Or, as Gibbard put it, "Rehearsal is very cerebral. You think about it then so that when you perform you don't have to think about it."

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