Mumford & Sons have released a new standalone single called “Blind Leading the Blind,” its first new music since last year’s Delta album. The group debuted the song live in 2016, initially recorded it early in the Delta sessions and spent the last 18 months “continually re-shaping, re-writing and generally re-imagining” the tune.

Frontman Marcus Mumford said in a statement, “‘Blind Leading The Blind’ has been a song we’ve had up our sleeves for some time, which ended up being a catalytic song for much of our work on Delta, its themes and feelings, but that we never got round to finishing in time to put it on the original release.”

He added, “We’re proud that we’ve finally finished it, as it feels like one of the most challenging songs, thematically, that we’ve put out there, both for ourselves and our audience.” The band was also inspired to finish the tune by winning the John Steinbeck Award last month.

Mumford & Sons have a tour of Asia set for November, with a run of U.S. holiday radio shows coming in December. They’re also set to headline Florida’s Okeechobee Festival next March.