The Dunwells are the latest players in the emerging West London folk scene to come to America. When they play the Belly Up, it will be for the first time. The latest UK folk invasion is a true multitude of aging genres, but no one seems to care. West London bands are the hot ticket right now. The Dunwells’ label calls them Celtic/American folk/rock/blues/pop, and everyone says “Mumford and Sons” or “Fleet Foxes” by way of comparison. I hear more early Fleetwood Mac than Mumford in the Dunwells, but I think what most fans are responding to, genre mystification or not, is the band’s unabashed musicianship and the passion that drives them during a live show. Joe Dunwell plays his guitar and sings like a hungry man.

The Dunwells make roots music with five-part bluegrass harmonies and a load of stringed instruments, including guitars and dobros and banjos and everything in between. The band is brothers David and Joseph, Rob Clayton and his cousin Jonny Lamb, and guitarist Dave Hanson. I asked Joe Dunwell about “Blind Sighted Faith,” the title track from their debut CD. Is it a subliminal reference to late ’60s Brit super-group Blind Faith? Dunwell says no, that the song was written during a stretch of band poverty and became their equivalent to Journey’s “Don’t Stop Believin’.”

But the Dunwells caught a break and managed to book themselves into all the major UK folk-rock festivals, where their hammering live shows generated buzz — real buzz, among real fans — a notion that is as outdated in a world gone digital as their music.

Los Lonely Boys also perform.

THE DUNWELLS: Belly Up Tavern, Tuesday, February 28, 8 p.m. $42 advance; $44 day of show.