Because the PCSBtv signal is carried by cable TV systems to the general public, copyrighted materials need permission or licensing in order to legally use them in a broadcast. If someone else made it, you will need permission to use it.
The use of copyrighted materials on PCSBtv is prohibited without written permission to broadcast from the copyright
The following web pages provide a good deal of information about the use of copyrighted materials:
More information about the process of licensing music and performances is available at the following sites: