It slows your breathing and reduces brain activity to such an extent that Weightless, written by Manchester band Marconi Union, is said to be the 'most relaxing song ever'.
The eight-minute track is so effective at inducing sleep, motorists have now been warned they should not listen to it whilst driving.
The band worked with sound therapists to get advice on how to make the most effective use of harmonies, rhythms and bass lines. The result on listeners is a slowing of the heart rate, reduced blood pressure and lower levels of the stress hormone cortisol.
Scientists played the song to 40 women and found it to be more effective at helping them relax than songs by Enya, Mozart and Coldplay.
The study - commissioned by bubble bath and shower gel firm Radox Spa - found the song was even more relaxing than a massage, walk or cup of tea.
For the astute reader, yes, the project was sponsored by a corporation, so there are ad plugs aplenty at the various links, and including in the video below. And I think the methodology is undoubtedly flawed. And overall, it's more advertising gimmick then anything.
All that aside, I find the whole thing very interesting, though I can't for sure say why. It's very much ambient music, but interesting nonetheless.
The entire track can be listened to here.
Video below gives a little synopsis of the project.