Deep underground in Virginia’s Luray Caverns sits the world’s largest musical instrument: The Great Stalacpipe Organ. The massive subterranean lithophone is comprised of 37 stalactites covering 3.5 acres that produce gentle musical tones when tapped with rubber-tipped mallets. It’s the only instrument of its kind in the world.

Great Big Story met with organist Otto Pebworth inside the cave for a conversation and performance. The organ’s stalactites can be played manually or like a traditional piano—when a key is pressed, it sends an electrical pulse up to the striker, which then vibrates the natural formations.

In the video above, Pebworth says, “To play the instrument that is utilizing our gentle Earth—it’s like you are becoming one with the instrument in a very true way.”

According to Atlas Obscura, the instrument was built over a three-year period in the mid-1950s by inventor, mathematician, and scientist Leland Sprinkle.

You can tour the Luray Caverns, which were first discovered in 1878 by a local tinsmith, but if you can’t get to Virginia anytime soon, take a sonic journey by listening to the sweet sounds of The Great Stalacpipe organ here.

[h/t The Kids Should See This]

Images via YouTube.