Like many before him, Mumford & Sons' frontman Marcus Mumford made his pilgrimage to Nashville as a young, aspiring musician. Although he's British, he found himself living in Denver about four years ago, and he drove with a friend across the U.S. to buy an acoustic guitar at Gruhn Guitars on Lower Broadway, in the heart of the city's honky-tonk district.

"I went back in there this morning and spoke to the guy who sold it to me. We had a nice chat," he told CMT.com during a Nashville tour stop in November. But with deadpan delivery suited to his native humor, he added, "I think he gets a lot of bands in there," causing the remaining band members -- Ted Dwane, Ben Lovett and Country Winston -- to crack up. "It wasn't quite like the emotional upheaval I thought it would be. I thought he would be weeping and I would be weeping, but it didn't work out like that."

His hand-picked Martin OM guitar has traveled countless miles since then, as Mumford & Sons have evolved from a rootsy, ragged bar band based in London, to an in-demand entity that sold out their U.S. tour and are now nominated for two Grammys (including best new artist) after releasing their debut album, Sigh No More, in the U.S. in early 2010.

Mumford & Sons will receive additional mainstream media exposure when they join the Avett Brothers in backing the legendary Bob Dylan during the Grammys show on Sunday night (Feb. 13). The show will be telecast live on CBS.

During the loose and casual interview, the young men spoke reverently about Nashville institutions like the Country Music Hall of Fame and Museum and the Station Inn bluegrass club, as well as country legends like Johnny Cash and Dolly Parton. In addition, they have modeled themselves after Old Crow Medicine Show, a young band that's mostly based in Nashville yet travels the world with original old-time music and an invigorating live show.

"They're truly inspirational in the way that conduct themselves and the way they see music," Mumford said. "For them, it's not a job. It's not a career. We feel like that, too, and having the opportunity to tour with them in Europe was sort of a dream come true for us. They never put their instruments down. They were always playing. We would be eating dinner and taking a rest, and they'd have these guitars that were always around, and they were just picking away in the corner and playing the whole time. That's the kind of attitude we aspire to maintain throughout our life as a band."

Like Old Crow Medicine Show, there's no full-time drummer in Mumford & Sons. However, the British group does employ piano -- and a banjo. It's not exactly a rock 'n' roll formula, but it suits them.

"I couldn't play any other instrument really, and I love playing piano," Lovett noted. "Winston was a banjo player, and we all ended up in a band together. It was all very accidental."

"On the record, there's a full [drum] kit on two songs, and the rest of it is a fleshing out of what we do live, where I play drums with my feet -- a kick drum and a tambourine. Then we added some cymbals and some shakers, like salt and pepper that you put on," Mumford said. "I guess it's fairly minimal percussion because we play percussive instruments -- the piano, the banjo, the acoustic guitar and the double bass (the upright bass rather than the electric bass) on a lot of the songs. You've got the high end covered with the banjo, the middle with the guitar, and the bass and the keys cover the low end. Really, if you just add a kick and a tambourine, we find that a lot of the time we forget we don't have a drummer. We all grew up playing in bands with drummers, and it's an integral part of the bands we've always been in. But we didn't really notice the transition to a band with no drummer."

"I think we had gone into the studio and met Markus Dravs for the first time, the guy who produced [the album], and he was talking about this relentless drive that he wanted to get into the record," added Dwane. "We were keen to capture that live energy, so I think not having a drummer, with Marcus playing that four-to-the-floor on the kick drum and with the bass, it does still give it that drive. It is quite infectious energy, hopefully."

"We were really just playing the instruments we had in our hands at the time," Mumford further explained. "I had just gotten back from Nashville and had a guitar. Winston had been teaching himself the banjo, and Ben played piano and Ted had just bought himself a double bass. We got in a room together and we had a few skeletal song ideas. We started playing and I guess we thought it sounded nice. We thought it sounded all right and then we started writing songs with that set-up."

Despite the lack of a drummer on tour, the band thrives with an undercurrent of electricity and dramatic vocals that can elicit screaming from even a Nashville crowd, notorious for stoic expressions, not standing ovations. From the balcony seats at the city's War Memorial Auditorium, which sold out months in advance, you could see people of all ages standing shoulder to shoulder on the floor.

"I love seeing folks with gray hair. That gives me a buzz because obviously the older you get, the more gigs you've been to, if you're a music lover. You probably have higher standards, so the fact that they come to our shows is ... slightly baffling," Mumford said with a laugh. "Yeah, it's been a nice spread."

The band is unfailingly polite in conversation, even as they constantly cut up with each other. Indeed, Mumford describes his own band as "just four dudes from London who don't really know what we're doing." When complimented on their sold-out tour, Mumford modestly replied, "It's pretty confusing, but it's fun."

Wait, confusing? With this much buzz?

"It's just a bit baffling because we've toured the U.K. quite a lot and worked really hard there and know a lot of people there, obviously, even from town to town," he said. "But in the U.S., it's such a huge place for a start, and so varied, and we feel like we haven't even scratched the surface in terms of touring here. But to be able to play the rooms that we've been playing on this tour is just kind of confusing."

Wrapping up the interview so the band can head to soundcheck, they were asked what they'd like an audience to take away from a Mumford & Sons show.

"We want people to feel like they're in the room with us and feel present and not feel like they're just observing something," replied Winston, who wryly suggested he got his "Country" nickname by being one of only a handful of banjo players in London. "We like to have a big party. We like to call them 'hoedowns,' but that's a little bit dangerous saying that in Nashville."