The Sky Orchestra

Luke Jerram's Sky Orchestra project "explores how one can perceive an artistic experience" whilst sleeping.
To do this, Jerram has "develop[ed] music specifically for sleeping people which is delivered out of the sky."

Quoting from the artist's website at length:

Seven hot air balloons, each with speakers attached, take off at dawn to fly across a city. Each balloon plays a different element of the musical score creating a massive audio landscape.

"Like whales calling in the ocean, the same sounds may be heard in succession passing from one balloon to another across the sky ..."

Many hundreds of people experience the Sky Orchestra event live as the balloons fly over their homes at dawn. The airborne project is both a vast spectacular performance as well as an intimate, personal experience. The music is audible, both consciously and subconsciously, to all those in the balloon’s flight paths.

Wired covered the project last summer, writing: "If you’re lulled awake by electronic music at daybreak, look up. The tune may be coming from the seven hot-air balloons in artist Luke Jerram’s Sky Orchestra as it bumps ’80s-synth-style ambient tracks from the heavens."
The Telegraph jumped in, reporting that "residents of Stratford-upon-Avon awoke yesterday to find a flotilla of hot air balloons drifting over their roofs serenading them with ambient music and readings from Shakespeare."
Last but not least, way back in 2004, the Guardian claimed that residents of Birmingham had been "helplessly lulled into deeper sleep at dawn yesterday morning, by specially composed music played from a flight of hot air balloons drifting over the dozing city... The flutes and oboes, bird song and whale calls, were based on scientific research to promote deeper and sweeter dreams."
However, it'd be interesting to see if something like this could be abused for political purposes, whispering subliminal messages into the sleeping, pre-dawn brains of the local electorate...
But it also raises an interesting paranoid-philosophical question: if you experience a particularly good night's sleep, and you live alone in the countryside somewhere, with neither witnesses nor neighbors, how do you know if the Sky Orchestra has – or has not – come floating through...?
Is this how myths begin?

(Huge thanks to Marilyn Terrell for pointing this out to me! Earlier on BLDGBLOG: Is that a geostationary banana in the sky – and what is it trying to say...?)