Music is meant to be shared. Apart from playing music life and sharing it with people that way also recordings, lyrics, melodies and so on may be shared, reused, ...
There are many ways of sharing music:
- Jam sessions
- CDdropping (see Bookcrossing)
In a capitalistic world of property and profits it seems like artists need to explicitly say that their music is meant to be shared: Free music under free content licenses. Of course also other ("non-free") music also needs to be shared to live (- otherwise it doesn't make much sense -) nevertheless in some cases the sharing may be illegal, the persons who share it called "pirates"...
There are several projects and communities on the internet for the sharing of (recordings of) music: