This Is the Oldest, Weirdest Instrument On Earth

In August 1878, hunters discovered a cool breeze coming from a small hole in Western Virginia and began digging to explore it.

• Andrew and Quint descended with only a candle for light • They spent months exploring the cave system • They discovered giant caverns connected by narrow passageways

• Largest cave system in the Eastern United States, covering 26 hectares • Ceilings and floors covered in stalactites and stalagmites • Underground lake discovered within the caverns

Now known as Luray Caverns, visited by half a million tourists each year.

The Cathedral chamber was used as a ballroom for dances and social gatherings in the 1920s due to its natural air conditioning.

In 1954, mathematician Leland Sprinkle visiting the caverns for his son's birthday observed a tour guide hitting stalactites with a mallet to produce musical tones.

• Sprinkle conceived turning the entire cave into a musical instrument • Construction began in 1954 and took three years to complete • First played in 1957 • The organ covers three and a half acres spread throughout the caverns

Officially known as the Great Stalacpipe Organ, located 260 feet below the surface, it is technically called a lithophone.

Sprinkle walked the caverns with a ladder, tuning forks, and mallets, hitting stalactites to find those with desirable pitches.

When a stalactite matched the desired concert pitch, Sprinkle used a disc grinder to shave it down to exact specifications.

• Form as slightly acidic water dissolves limestone and redeposits it • Grow at approximately 16 cubic centimeters every 120 years in this cave • Growth rate depends on water flow through the cave • Larger stalactites produce lower notes due to their resonant frequency

A stalactite's resonant frequency depends on its size, shape, and the elastic modulus of limestone, allowing Sprinkle to achieve specific musical pitches.

• Custom-built brackets attached to each musical stalactite • Electrically operated plunger with rubber tip strikes the stalactite • Causes the stalactite to vibrate and produce sound

Steel bolts were added to each musical stalactite and electric guitar pickups detect the vibrations they produce.

A guitar pickup consists of a coil of wire wrapped around a magnet that detects ferromagnetic vibrations and induces electrical current.

Detected signals are amplified, mixed, and played back through speakers to address the variable volume of distant stalactites throughout the cavern.

Guitar pickups created an unexpected problem: one of the keys picked up a local AM radio station signal.

The radio interference turned that key into an unintended sampler, broadcasting radio content when played.

If Sprinkle had chosen actively growing stalactites, the organ would eventually go out of tune as they continued growing and changing their resonant frequency.

Sprinkle carefully selected inactive stalactites to minimize future tuning issues, though theoretically the instrument could drift out of tune over geological timescales.

Musician Rob Scallon described the experience as grounding, surreal, and beautiful, with unique properties impossible to replicate elsewhere.

• Notes are scattered throughout the cavern at different distances • Immense natural reverb creates hauntingly beautiful sounds • Notes positioned in different locations have varying reverb characteristics • Pure, beautiful tones amplified selectively by the cave's acoustics

The organ is a fusion of human creativity and geological time, built upon structures created drop by drop over unfathomable years.

The project transformed an already magnificent natural structure into something even more beautiful while raising questions about modifying ancient formations that took eons to create.