f you are broadcasting over the internet without any form of licensing,
it is not illegal. Unlike standard radio (going via FM/AM or DAB) you do not need a 'license' to broadcast, to own that wavelength on an AM/FM band so to speak. That is the beauty of the internet, no one 'owns' it and therefore it is yours to use how you like, there is no limit to the number of streams you can run.
However, if the content of your stream includes any copyrighted material - you are at risk and may be breaking the law if you do not hold the permission of the copyright holder - which for most commercial music is the record label or the artist themselves.
Music licensing is available for individuals and organizations looking to stream copyrighted material online legally. A single fee is usually paid to the licensing body, which in turn is then fairly distributed to the copyright holders.
The following links to music licensing bodies may be of help:
USA: 3rd Party 'umbrella' Licenses for web broadcasting:
www.loudcity.net
www.swcast.com
www.bmi.com
www.ascap.com
www.soundexchange.com
UK:
www.ppluk.com
PPL - the UK broadcast royalties collection society
www.mcps-prs-alliance.co.uk
The MCPS-PRS Alliance
Germany:
www.gema.de
www.gvl.de
France:
www.sacem.fr
Netherlands:
www.bumastemra.nl
So by that, we just need to pay for streaming copyrighted music?