Free music
Free music is music that gets published under a free content license.
Music gets shared anyway and also "non-free" music needs to be shared to live (- otherwise it doesn't make much sense) - but with free music the artists themselfes support the sharing of their work. (In a capitalistic world of property and profits it seems like artists need to explicitly say that their music is meant to be shared...) So with free music pople don't need to fear to be called "pirates"...
For example by music (and film) industry by putting pressure on file sharers and incorporating copy preventing mechanisms (DRM) into their products, artists experiencing the situation that for example copyright collectives forbid them to freely share their own music because they don't own the the rights anymore, and so on - and on the other hand the success of free software and free content projects like Wikipedia raised awareness for intellectual proprety and the freedom of sharing. Out of this awareness a new movement for explicitly free music was born.