Mumford and Sons Close US Tour With 'Mental' New York Gig

Mumford and Sons have a lot to be happy about. The young band has outsold Eminem on iTunes week after week, their 2009 debut record, 'Sigh No More,' entered Billboard's Top 20 in September and their North American fall tour sold out in record time.

On Tuesday night, when the quartet performed 'Lady of the River,' a song they worked on on with opener King Charles, their British touring mate gave them a surprise they'll never forget. "This is the first song I wrote when I started playing country music with Mumford and Sons," King Charles said midway through the performance at New York's Terminal 5. "I want to give this song to Mumford and Sons. This is now a Mumford and Sons song."

After dropping his jaw in utter shock, frontman Marcus Mumford graciously accepted the gift by hugging King Charles before the musicians went back to singing. "It's genuinely one of my favorite songs of all time," Mumford said.

After touring 17 states, the UK band didn't show any sense of exhaustion. The two-hour set was filled with monstrous renditions of tracks from 'Sigh No More,' humorous banter between songs and continuous cheering from the crowd. "You're very kind, New York," keyboardist and singer Ben Lovett said. "You guys are better than last night," he added, referring to Monday's crowd at the same building.

"This is the last stop on our tour, and it's been a lot of fun," Mumford then told the audience, which was rumored to include David Bowie among its ranks. "Let's go f---ing mental!"

The band also performed 'Lover of the Light' and 'Below My Feet,' two new songs that will likely be part of the band's upcoming record, which they hope to start recording after resting for a couple of months. While 'Below My Feet' follows Mumford and Sons' normal sound, 'Love of the Light' strays from their usual bluegrass-country blend in favor of edgier rock, which was magnified even more during the explosive performance.

Fittingly, Mumford and Sons ended their set with their biggest hit, 'The Cave.' When the crowd kept asking for one more song, they reassured everyone that the band would be back to play next year.