The Great Stalacpipe Organ, located in Luray Caverns, Virginia, is a unique musical instrument that uses the natural formations of stalactites to create music. Discovered in 1878, the caverns are the largest in the Eastern United States and attract half a million visitors annually. The organ was conceived by Leland Sprinkle in 1954, who used electromechanical mallets and electric guitar pickups to turn the cave into a lithophone. Sprinkle spent three years selecting and tuning stalactites to concert pitch by shaving them to the desired frequency. The organ covers three and a half acres, with notes scattered throughout the cave, creating a hauntingly beautiful sound with immense reverb. The project is a testament to human ingenuity and the natural beauty of the caverns, combining technology and nature to produce a unique auditory experience. Despite challenges like radio interference, the organ remains a marvel of acoustic engineering, with its stalactites carefully chosen to avoid growth that would detune them over time.