Stars are huge balls of gas and they vibrate or oscillate. This oscillation can be observed by recording slight changes in the colour of the star. This can then be converted into sound, although the frequency is so low it has to be speeded up.
Every star makes a different noise, and this has inspired Sylvie Vauclair is an astrophysicist at the French Institute for Research in Astrophysics and Planetology, and Claude-Samuel Levine, a musician specialising in electronic music, to use the sound of the stars to compose music. They call it “Nouvelle Musique des Spheres”, The New Music of the Spheres. This takes it’s name from the Greek theory that the planets were attached to crystalline spheres which carried them around the Earth, and the mathematical relationships between these orbits was reminiscent of the relations which Pythagoras had discovered between musical notes.
Below you will find links which will let you listen to music composed from the sounds of stars.
References
Recording the Sounds of Stars
http://www.telegraph.co.uk/science/space/8114694/Stars-song-captured-by-scientists.html
http://news.bbc.co.uk/1/hi/sci/tech/7687286.stm
Music Created from Star Sounds
http://www.cslevine.com/etoiles/youtube_spheres.htm
http://www.odilejacob.com/catalogue/art-and-literature/music-dance/music-of-the-spheres_9782738130365.php
Music of the Spheres in Greek Philosophy
http://en.wikipedia.org/wiki/Musica_universalis