One thing I try and do with my music is tailor my playlist to the mood and nature of my activities in LOTRO. This isn't necessary but I find it adds to the gameplay. The first "type" of music I want to recommend is already present in the game. This of course is your soft instrumentals that have a nice calm, mood to them (I'm no music theorist or lingo expert so excuse the descriptions). They are good to listen to in low stress situations like when you are exploring the wilds, farming nodes, or running delivery quests. The first songs I want to recommend to you is by a (believe it or not) progressive death-metal band called Becoming the Archetype. I find that Hardcore/metal bands like BTA write some awesome instrumentals that go unnoticed for obvious reasons.
*Song links are all from Youtube and are not my uploads*
Song #1: Night's Sorrow by Becoming the Archetype, album: Terminate Damnation ~ (classical guitar instrumental)
Song #2: St. Anne's Lullaby by Becoming the Archetype, album: Dichotomy ~ (classical guitar instrumental)
Song #3: Music of the Spheres: Requiem Aeternam, Pt. 1 by Becoming the Archetype, album: Celestial Completion ~ (piano instrumental)
The next are what I call the "rainy day folk songs". These would also be ones I'd use for low stress situations in-game but they definitely have a different feel (not to mention vocalists). They hold more of a sad mood to them so to speak. These songs don't have lyrics that really reflect anything in LOTRO really, so they can take away some immersion.
Song #4: Idaho by Josh Ritter, album: In the Dark: Live at Vicar Street ~ (a man longing for his home)
Song #5: The Shore by Basia Bulat, album: Heart of My Own ~ (a woman longing for the shore/love)
Song #6: By Your Side by House of Heroes, album: The End is not the End ~ (heartbreaking story of losing a brother in war)
The last kind of song I want to leave you with (in this post anyways) is the inspiring type. I love all kinds of music, from bluegrass to death metal. However, one thing most of the albums that I own have is positive or "Christian" lyrics. I find it better to be uplifted than to be stressed out. So here are some positive, inspiring songs...
Song #7: Commissioned by Kings by Oh, Sleeper, album: Son of the Morning ~ (WARNING: HARDCORE, lyrics about acknowledging faults, unleashing strength)
Song #8: Field of Daggers by House of Heroes, album: The End is not the End ~ ( peace, false kings)
Song #9: Phoenix by For Today, album: Breaker ~ (WARNING: HARDCORE "you've been called to relinquish fear, can you hear it?")
Song #10: Iron by Woodkid ~ (Just an epic song really)
These are just a few songs that I listen to while playing LOTRO. If you like any of them please do not download them; instead, buy them and support the musicians!