The Grooveshark online music service has many users all over the world, but it has the small defect that it can only be used via the web browser, unless you have an application like Grooveshark Desktop installed on your Mac.
Identical but independent
Grooveshark Desktop really only covers one specific function, that is to provide this free streaming music system with a user interface, in such a way that you will be able to do without the Internet browser to access it.
As you would do from the main page of the service, with Grooveshark you will be able to search for music, create and handle playlists and you will even be able to listen to music on its genre based radio broadcasts.
It also offers the possibility to upload music to your account on the Grooveshark service and you will be able to modify your account as if you were using a browser.
Therefore, if you wan to enjoy Grooveshark without having to access it with a browser, all you have to do is download Grooveshark Desktop, its free.