Folk rockers the Low Anthem are currently headlining their first U.S. tour in support of their album Oh My God, Charlie Darwin, on which they took a unique approach to creating a sonic identity: recording antique, pedal-pumped reed organs. Their 1915 Estey organ is of special interest, as it was played by an Army chaplain in France during World War I. The band has also found organs in Vermont, Indiana, and North Carolina. Their organic sound is a joy to experience and a perfect complement to the voice of keyboardist Ben Knox-Miller, who took time out to speak with us about this unique quest.

Why did you seek out antique pump organs for the record?
We weren’t looking for one. We weren’t satisfied with any of the digital keyboards’ organ sounds. It appealed to us more that this was actually air moving across reeds and there was some element of chance, a real physical thing happening, and the beautiful woody resonance.

So you never thought you could get the same sound by using samples?
No. The pump organs are very unpredictable and a lot of that has nice charm to it.

Who were some of your influences?
Neil Young uses a lot of pump organs. We recently saw him play and he played solo acoustic on the pump organ. Tom Waits also uses pump organs on his recordings.

On “To Ohio,” which organ was used?
The Estey portable pump organ. There’s a nice blend of the traditional pump organ that sounds kind of like a mockup of an electric organ sound — kind of corky, naturally woody, and crackly. On “The Ghosts who Write History Books,” by contrast, that’s a really clean organ sound.

What about on “Cage the Song Bird”?
That was the Estey again, the predominant organ we recorded with. We also have a harmonium on stage, and a melodeon we just bought. It’s from 1850. We found it in Newcastle, Indiana.

Think a B-3 is vintage? One of the Low Anthem’s vintage reed organs is this turn-of-the-century model from Vermont organ builder Estey, established in 1840.