The never ending circle of underground music getting mainstream is exhousting. One of those places to discover new sounds is BIRP!.
Every month +100 indie tracks chosen by the boys from birp.fm are available for streaming buying and downloadable. Like always most of the time you can find a few tracks which are shining like a diamond.
So if you want to discover the mainstream before it’s getting mainstream, listen to the tracks compiled by birp.fm. This is tracklist from this month: http://www.birp.fm/playlist/2014/march-2014