- Hidden deep beneath the Cumberland Mountains in Grundy County, Tennessee, lies one of the world's most magical, musical adventures.

The Caverns Sessions, 3 million years in the making, pure acoustics, offer music from the heart of the American experience.

Center stage and deep inside the mountain.

This week welcoming, the Milk Carton Kids ♪ I'll be in New York Send for me ♪ - It's deep down musical diversity, with the Caverns Sessions, coming up next.

(crowd cheers and applauds) (guitars playing) (guitars playing) ♪ Go ahead stomp your feet on the floorboards ♪ ♪ Clap your hands if that's really ♪ ♪ What you came here for ♪ ♪ Hang a prayer for luck over the door ♪ ♪ They promised me heaven ♪ ♪ I was hoping for something more ♪ (guitars playing) ♪ Stomp the drum good and loud ♪ ♪ Shake the walls down ♪ (guitars playing) ♪ Scream and holler, jump about all together now... ♪ ♪ Ain't nothing like a lie to gather 'round... ♪ ♪ They promised me heaven ♪ ♪ I was hoping for so much more ♪ (guitars playing) ♪ Heaven are we wasted ♪ ♪ Heaven have we been out long ♪ (guitars playing) ♪ Heaven are you waiting ♪ ♪ Heaven this going wrong... ♪ ♪ Pour me up another, this is gonna hurt ♪ ♪ Should've known it all along ♪ ♪ Heaven better shake it ♪ ♪ Heaven better make it strong ♪ (guitars playing) (guitars playing) (guitars playing) (guitars playing) (audience members laughing) (guitars playing) ♪ Go to hell, stomp your feet on the floorboards ♪ (guitars playing) ♪ Step in time, count 'em in ♪ ♪ Just to be real sure.... ♪ ♪ This ain't no revolution anymore... ♪ ♪ They promised me heaven ♪ ♪ I was hoping for something more ♪ (guitars playing) ♪ Heaven are we wasted ♪ ♪ Heaven have we been out long ♪ (guitars playing) ♪ Heaven are you waiting ♪ ♪ Heaven this going wrong... ♪ ♪ Pour me up another, this is gonna hurt ♪ ♪ Should've known it all along ♪ ♪ Heaven better shake it ♪ ♪ Heaven better make it strong... ♪ ♪ Heaven better shake it ♪ ♪ Heaven better make it strong... ♪ (audience cheering) - This is definitely one of the top 10 cave shows we've ever done.

(audience laughing) I gotta say this is, this is a really special one.

I can't believe they found one that had bathrooms and concessions all built out in it, because normally it's just like bats and stalactites, stalagmites.

But this one is like, pretty nice.

(audience laughing) - Did you read the Wikipedia entry on caves earlier?

Is this what happened?

- No, and if I did, I would know which were the stalactites and which were the stalagmites.

But I bet I bet half of you right now are itching and jump outta your seats and tell me which one's which.

Isn't it hard to know something that the person on stage doesn't know, and not jump up and say it, huh?

Hold it, keep it to yourself.

(audience members laughing) - There's a lot that qualifies in this case.

Let me tell you.

(audience laughing) - Anyway, the stalactites are the one that come from the top.

- What?

(audience cheering) - [Joey] That was a 50-50 right there.

(audience laughing) - You know, you've always been a 50-50 kinda guy.

- That's right, that's why I like being in a duo.

Here we go.

- One, two, three.

(audience members cheer) (guitars playing) ♪ You said it just right ♪ ♪ I never stay ♪ ♪ Long enough to fight ♪ ♪ I just run away ♪ ♪ And it's you my love ♪ ♪ It's you i'm running from ♪ (guitars playing) ♪ You were mistaken ♪ ♪ You are to blame ♪ ♪ Lately I've taken ♪ ♪ To getting my own way ♪ ♪ Yes, it's you my love ♪ ♪ It's you i'm running from ♪ (guitars playing) ♪ I'll be in New York ♪ ♪ Send for me when you want more ♪ ♪ I'll be in in New York ♪ ♪ Without you like before ♪ ♪ I'm never lonely ♪ ♪ Off making trails ♪ ♪ Passed on the only ♪ ♪ A woman dressed in veil ♪ ♪ Oh, it's you my love ♪ ♪ It's you i'm running from ♪ (guitars playing) ♪ When your bed's empty ♪ ♪ Will I appear ♪ ♪ In dreams you so badly ♪ ♪ Wish could draw me near ♪ ♪ Though it's you my love ♪ ♪ It's you i'm running from ♪ (guitars playing) ♪ I'll be in New York ♪ ♪ Send for me when you want more ♪ ♪ I'll be in New York ♪ ♪ Without you like before, oh, oh... ♪ ♪ Oh... ♪ ♪ Oh... ♪ ♪ Oh, o-oh.... ♪ ♪ Oh, o-oh... ♪ (guitars playing) (guitars playing) ♪ I'll be in New York ♪ ♪ Send for me when you want more ♪ ♪ I'll be in New York ♪ ♪ Without you like before ♪ ♪ I'll be in New York ♪ ♪ Send for me when you want more ♪ ♪ I'll be in New York ♪ ♪ Without you like before, oh, oh... ♪ ♪ Oh... ♪ ♪ Oh... ♪ ♪ Oh, o-oh... ♪ ♪ Oh, o-oh... ♪ (applause and cheering) (applause and cheering) (guitars playing) (guitars playing) (guitars playing) (guitars playing) (guitars playing) ♪ Above the plains of Omaha ♪ ♪ I think of all the suffering I saw ♪ (guitars playing) ♪ The soaking of the pavement ♪ ♪ Sprawled upon a land without a law ♪ ♪ Everything I loved ♪ ♪ Everything I found or I hoped for... ♪ ♪ Frightened, I'm surrounded ♪ ♪ Who else is there to turn to anymore ♪ ♪ Oh, I held out my arms ♪ ♪ Oh, I held out my arms ♪ ♪ Held out my arms... ♪ ♪ Oh, o-oh... ♪ (guitars playing) ♪ There was a time I spoke the truth ♪ ♪ But my younger years were wasted on my youth ♪ (guitars playing) ♪ Somewhere I awakened with a crack ♪ ♪ To a pounding on the roof ♪ ♪ Sure, I heard the sound as evidence ♪ ♪ Or better yet, as proof... ♪ ♪ I was as naked as the day that I was born ♪ ♪ Beneath the fullness of the moon ♪ ♪ Oh, I held out my arms ♪ ♪ Oh, I held out my arms ♪ ♪ I held out my arms... ♪ ♪ Oh, o-oh... ♪ (guitars playing) ♪ Far away I hear singing ♪ (guitars playing) ♪ Far away, a song... ♪ (guitars playing) (guitars playing) (guitars playing) (audience cheering) ♪ The blinding light of morning came ♪ ♪ Flooding through the window like a friend ♪ (guitars playing) ♪ Like a wild revelation ♪ ♪ Like a shining invitation to attend ♪ ♪ Spoken as a prayer ♪ ♪ Unbroken by despair I make amends ♪ (guitars playing) ♪ The love inside our hearts ♪ ♪ Is the only kind of savior we've been sent ♪ ♪ Oh, I held out my arms ♪ ♪ Oh, I held out my arms ♪ ♪ I held out my arms... ♪ ♪ Oh, o-oh... ♪ (guitars playing) (audience cheering) - Thank you.

(audience cheering) - Thank you very much, we're called the Milk Carton Kids.

Such an honor to be here underground.

(audience cheering) I just want you to know this is, this is our whole band.

(audience laughing) This, you know, this is not like the special acoustic version for the underground show.

This is the whole band, this is all it's ever been.

Thank you.

(applause and cheering) This is all it ever is, in the van, in the studio, in the hotel.

(Kenneth laughing) Just the two of us.

- It's been 12 years.

You'd think that we've run out of things to talk about, and according to my partner here we have.

But it just really feels lonely.

I don't know if any of you are in folk music duos, but about the seven-year mark, it gets lonely.

(audience members laughing) Ask Simon, ask Garfunkel, ask Don, ask Phil, ask any of them, gets lonely.

- All right.

- Yeah, true story though.

At the beginning, Joey, no joke, it was 2010 and he seriously lobbied to add a kick drum player to the band.

Just a, (mimics drum).

- Well, I wanted to be the kick drum player, and I'm still lobbying for it.

(audience laughing) - It seems like he could figure out how to do this and that at the same time.

- I do, I think so too.

I'm gonna try it on this next, this next song is a five-minute breakup dirge, and I'm gonna add imaginary kick drum throughout the whole thing.

(audience members cheering) Thank you.

(guitars playing) (cheering) (guitars playing) - No don't.

- Don't join him.

(audience laughing) (guitars playing) ♪ The clouds move over Pontiac skies... ♪ ♪ Their silent thunder matches mine... ♪ (guitars playing) ♪ I know this feeling from long ago... ♪ ♪ I wondered was it gone, now I know ♪ ♪ So when she calls don't send her my way ♪ ♪ When it hurts you'll know it's the right thing ♪ ♪ Michigan's in the rear view now... ♪ ♪ Keep your hands where I can see 'em... ♪ (guitars playing) ♪ You took the words right out of my mouth... ♪ ♪ When you knew that I would need 'em... ♪ (guitars playing) ♪ What am I supposed to do now... without you ♪ ♪ Without you... ♪ (guitars playing) (guitars playing) ♪ It's unannounced like you'd expect it ♪ ♪ Among broke down brake lines and Motown records ♪ ♪ And all that's left is a blind reflection ♪ ♪ But you know what's coming and you regret it ♪ ♪ So when she calls don't send her my way ♪ ♪ When it hurts most it's the right thing ♪ ♪ Michigan's in the rear view now ♪ ♪ Keep your hands where I can see 'em... ♪ ♪ You took the words right out of my mouth ♪ ♪ When you knew that I would need 'em... ♪ (guitars playing) ♪ What am I supposed to do now... without you ♪ ♪ Without you ♪ (guitars playing) ♪ Michigan's in the rear view now ♪ ♪ Keep your hands where I can see 'em... ♪ (guitars playing) ♪ You took the words right out of my mouth ♪ ♪ When you knew that I would need 'em... ♪ (guitars playing) ♪ What am I supposed to do now... without you ♪ ♪ Without you... ♪ (guitars playing) (guitars playing) (guitars playing) (guitars playing) (applause and cheering) - Thanks for coming out.

♪ Did you ever think the earth ♪ ♪ Would shake for me once more ♪ (guitars playing) ♪ I wanna see the sky light up ♪ ♪ Over this city left for poor ♪ (guitars playing) ♪ Everybody's screaming ♪ ♪ And no one here can ask what for ♪ (guitars playing) ♪ And I just can't shake this feeling ♪ ♪ That we're out of luck and nothing more ♪ ♪ A pound of dust, a holy war, a photograph ♪ ♪ I begged and I swore ♪ ♪ But I still want a little more ♪ (guitars playing) ♪ Run the luck out of this town ♪ ♪ A book and crown ain't no disguise ♪ (guitars playing) ♪ I'm left to stop the bleeding ♪ ♪ With a hope to realize ♪ (guitars playing) ♪ My misery is teeming ♪ ♪ My heart could be stealing yours ♪ (guitars playing) ♪ And I just can't shake this feeling ♪ ♪ That we're out of luck and nothing more ♪ ♪ A pound of dust, a holy war, a photograph ♪ ♪ I begged and I swore ♪ ♪ But I still want a little more ♪ (guitars playing) (guitars playing) ♪ And I just can't shake this feeling ♪ ♪ That we're out of luck and nothing more ♪ ♪ A pound of dust, a holy war, a photograph ♪ ♪ I begged and I swore ♪ ♪ But I still want a little more ♪ ♪ It's okay to tear the pictures ♪ ♪ From the frames that hold them still ♪ (guitars playing) ♪ Rattle all the cages ♪ ♪ Gather enemies on Capitol Hill ♪ (guitars playing) ♪ Yell at the sky ♪ ♪ Some kind of ideal bill... ♪ ♪ And I just can't shake this feeling ♪ ♪ That we're out of luck and nothing more ♪ ♪ A pound of dust, a holy war, a photograph ♪ ♪ I begged and I swore ♪ ♪ But I still want a little more... ♪ ♪ Yeah, I still want a little more... ♪ (audience cheering) - Thank you!

- All right, thanks for being here.

We'll see you next time.

(applause and cheering) ♪ ♪ ♪