Lovely abstract piece by Alvaro Posadas. Trapcode Particular v2 was used.
music: Black To Comm 'Amateur' Alphabet 1968 2009
Here is another by Alvaro:
And one more:
Music: Amon Tobin 'Big furry head'
I'm not sure how Alvaro makes these animations. My best guess is he is using expressions to guide the Emitter and he uses the Aux system.