Mumford and Sons is, by now, pretty familiar with Los Angeles.

The four-piece folk rock band from London has played this city four times—each time at a larger venue than the last.

The progression has gone from the Hotel Café, to the Troubadour, followed by the Music Box and then Monday night, the Palladium—which the band sold out.

Playing larger venues obviously translates to increased popularity, but Mumford and Sons doesn’t give off an attitude of growing too big for its British britches.

In fact, on Monday night, there were intimate moments when the group seemed almost in denial of the growing largeness of its operation.

Lead vocalist Marcus Mumford briefly spoke between many of the songs, annunciating so softly that it was difficult to hear him.

And at another point, the band sang an acoustic version of the song "Sister."

It was a beautiful rendition, but again, difficult to hear. The crowd had to squeeze in tightly in order to make out the sounds of the delicate four-part harmonies sans microphones.

During such moments, the show was like witnessing the external manifestation of a band’s internal struggle: reconciling its adoration for moments of stripped-down quaintness with the overall excitement about its bourgeoning success.

But in a way, that duality defines much of the band’s debut album, "Sigh No More," on which many songs begin softy and then build into rousing, thumping, kick-drum and banjo-driven folk rock gems.

Opening with the title track, “Sigh No More,” the band unleashed a nearly two-hour set, living up to its reputation for energetic and musically awe-inspiring live performance.

Impressive was not only Mumford’s ability to translate his recorded voice, both brawny and effortless, to the stage, but also impressive were the group’s harmonies, which have been nearly perfected.

All managed to sing in tune while dutifully playing instruments. Mumford handled guitar and drums while “Country” Winston Marshall mostly played the banjo. Ben Lovett played the accordion and keyboard with an energy unmatched, and Ted Dwane played the string bass.

And for the first time on one of the band’s United States tours, two musicians played horns during selected songs, giving the lovely “Winter Winds” its full, intended, sweeping sound.

“Little Lion Man” and “The Cave” evoked the strongest crowd reactions, as the euphoric fans danced and sang along to the band’s most recognizable songs.

But the majority of the fans knew the words to every song, radio-hit or not—every word that came from Marcus Mumford’s mouth—with literary lyrics of faith and love loss, rediscovery and relationships—was echoed by 4,000 admirers.

And during those heart-pounding moments, when a roomful of that many people is singing along to a stirring song like “Awake My Soul,” the thought of losing some of Mumford and Son’s quaintness because of larger venues begins to seem like a worthwhile trade off.