Who needs a synthetiser?

Pulsar SOUND

"Pulsars are highly magnetized, rotating neutron stars that emit a beam of electromagnetic radiation. The observed periods of their pulses range from 1.4 milliseconds to 8.5 seconds.
[1] The radiation can only be observed when the beam of emission is pointing towards the Earth. This is called the lighthouse effect and gives rise to the pulsed nature that gives pulsars their name. Because neutron stars are very dense objects, the rotation period and thus the interval between observed pulses is very regular. 
For some pulsars, the regularity of pulsation is as precise as an atomic clock.
[2] A few pulsars are known to have planets orbiting them, as in the case of PSR B1257+12. Werner Becker of the Max Planck Institute for Extraterrestrial Physics said in 2006, "The theory of how pulsars emit their radiation is still in its infancy, even after nearly forty years of work [3]." (via IDNMitigationAPIs)

Top 10 Incredible Sounds / Listverse

http://listverse.com/2010/01/08/top-10-incredible-sounds/

Slow Down Unidentified Sound

Booming Sands
Sounds of Ganymede's magnetosphere
Pulsar SOUND
EXTREMELY Close Lightning Strike
Disinformation "Ghost Shells"
Concorde breaking the sound barrier 
Space Dust 
Concorde breaking the sound barrier
Wow! Signal 
Bird sounds from the lyre bird - David Attenborough - BBC wildlife

Another Link!

Sound of space. Sound from Jupiters Moon Ganymede