P2P Music is formed by two small applications: a client and a server. Both included in the same pack. The server application has to be launched on the PC that is going to play the music and the client will have to be launched on those computers on which the music wants to be heard. Once they have connected to the server's IP over the LAN, all the clients will listen to whatever is being broadcast by the server. Any sound that is active on the server (including Windows sounds or messenger notifications).
P2P Music Server is very easy to configure, all that has to be indicated is the sound source that is going to be broadcast through the 2398 UDP port.
P2P Music Client doesn't even need configuration, except the IP address of the server computer and the playback volume. To listen, the port used is UDP 2399.