this is some info from another radio station (
http://www.wfuv.org/audio/streamdmca.html ) :
<snip>
The Digital Millennium Copyright Act (DMCA) is a U.S. law, passed in 1998, which regulates many aspects of Internet activity. It was established, presumably, to protect the copyrighted material of artists, scientists, writers, etc., in these times of growing technology. Part of this act establishes that the recording industry would have a right to collect royalties for their performers based on Internet "airplay."
It took a while for that to kick in, but in 2003 - amidst much debate and confusion - a set of rules and royalties was established for webcasters to follow. In order to track what songs are played, webcasters must submit thorough reports on every song played by every listener.
<snip>
Some of these DMCA rules outline restrictions on the frequency some songs can be played.
In any 3-hour period, we can webcast:
* No more than 3 songs from one album;
no more than 2 played consecutively
* No more than 4 songs from a set/compilation;
no more than 3 played consecutively
* No more than 4 recorded songs by the same artist
(live studio appearances are okay)