The origins of this alternative way of listening to dance music dates to 1969 when the idea first emerged in the Finnish science fiction movie Ruusujen Aika. The concept of outdoor parties without a traditional speaker system relying, instead, on the use of wireless headphones to deliver music to the participants, was then propagated by environmentalists in the early 1990s to minimize noise pollution and disturbance not only to people, but also to local wildlife. Since 2000, Silent Discos have been gaining popularity among young party goers and (also in the form of silent gigs, concerts based on the same principle) by major music festivals, for example the Glastonbury Festival.