There is a Co-op food shop in a village near where I live that is open until late in the evening. It has a wide pavement outside and the local youths congregate there sheltering under the awning.
Unfortunately the behaviour of these youths caused a problem for shoppers. I expect the takings went down due to people shopping elsewhere. However if you go there of an evening now you will see no youths in the vicinity. This is because the manager has installed a cheap and ingenious 'youth deterrent.'
He installed a speaker outside the shop which plays classical music. This music is only on in the evening and it does not play inside the shop so i can only assume he is not a fan of this genre. It would seem also that the youths in the area are also not fans because this music has proved very effective in keeping them away.
I find it very sad that these young people do not like this type of music when it is often so uplifting.