Their meteoric rise came at a time when American bluegrass and bluegrass-inflected music has never been better, and their hiatus is now an opportunity for their fans to learn more about it.
Here are the best bands and artists that are influenced by bluegrass and yet still accessible to a mainstream audience.
Trampled by Turtles
Trampled by Turtles sounds goofy, but they're not.
The band is an unusual pairing of virtuosos who look like they would be out of place anywhere other than behind their instruments and a younger lead singer who seems born for the part. They take on dramatic themes, such as loss, pain, and friendship, and they have the chops to pull it off. Whenever possible, they play at breakneck tempo.
Although the band's instrumentation is bluegrass -- guitar, banjo, mandolin, fiddle, and bass (although the bassist plays an acoustic guitar bass rather than an upright bass) -- they're not so twangy that those who aren't fans of bluegrass can't appreciate what they're doing.
America hasn't figured it out yet, but Hoots and Hellmouth is the best band in the country.
They once were more bluegrass than they are now. In the past two years, they've lost a guitarist and added drums, and the guy who once was primarily their mandolinist/banjoist now spends a lot more time behind the organ. Furthermore, the frontman Sean Hoots' fingerstyle (rather than flatpicked) guitar playing is unorthodox for bluegrass.
That doesn't take away from how great this group is. Hoots is not only a great musician and singer, he also is a brilliant songwriter. His verses reflect a dedication to getting the words right and feature a worldly but not cynical sensibility. The band's Philadelphia roots come out in its music, but its appeal is universal.
Every Hoots and Hellmouth song is worth listening to, although often they take more than one try to appreciate. Partly that's a credit to Hoots' songwriting, but it also demonstrates how tight the band is. Each number has clearly been rehearsed hundreds upon hundreds of times, without losing any of its vitality. The band also improvises and edits each one, making it worthwhile to listen to new live sets. The group's obvious love for their music is best demonstrated by the fact that they can put on an amazing show, holding nothing back, even if virtually no one is there to watch them.
Everyone's heard Wagon Wheel, hopefully.
While Old Crow may be a little too twangy for most, they're not a one-hit wonder. It's worth digging a little deeper into their work.
This is a Portland-based quartet. Two guitars, mandolin, bass, and harmonies.
Mostly they are about jamming and quick, catchy tunes. While they can sometimes verge on the silly or pointless, they're also capable of intricate, wistful tunes. If it's not obvious from their music, they play the part -- they are genuinely unkempt and dirty-looking.
This super-group. The Punch Brothers' leader, Chris Thile, was previously a member of Nickel Creek, for those who remember that slice of the late '90s. He's an amazingly talented mandolinist, and a very clever songwriter, even if he does sometimes push a concept and his singing voice -- which is serviceable but not as ranging as he seems to think -- too far.
The Punch Brothers' attraction lies more in the individual members' mind-blowing talent than in their musicianship, which is a compliment to the former rather than a criticism of the latter. Each of the five is at the top of his game on his instrument, but they're not above going way outside the bluegrass genre. In particular, they do a few Radiohead covers that somehow make more sense than you would think possible.
"Rye Whiskey" is their most famous and approachable song, but not necessarily representative of their work, because no song could be -- they cover too many genres and styles.
The infamous Stringdusters are not far from a straight-up bluegrass group. They're good enough, though, to have broad appeal.
This sister-brother-brother combo is too young to have a filled-out body of work. But they show amazing promise.
William Elliott Whitmore's music is a little difficult to define, but he has described it as "bluegrass rustic soul music." We're pretty far from the arena rock of Mumford at this point. It's just Whitmore with a guitar or banjo, and sometimes a kick drum. He is very clever at getting the most out of those limited tools, especially considering that he is not a naturally talented singer. His voice would sound strained and raspy rather than earthy or weathered if it wasn't for his evocative lyrics and riffs.