As we approach St. Patrick's Day, I note two good audio sources of Irish music and culture.
Live Ireland is a pretty good online radio station playing a wide selection of traditional music, and modern "trad-related", and rebel music etc. It's not overladen with talk or ads (rare in fact). See: http://my.liveireland.com/
The other one, for users of iPhones (I am not sure if available for Android phones), the RTE Radio Player app is pretty smashing good. From this app you can access all RTE radio channels, live, or recap, and that includes RTE Raidio na Gaeltachta, and they play a fair bit of core traditional Irish music (and if you're learning Irish, or speaking it, you'll hear nothing but Irish on this channel).
So there you go.