Located deep in the Luray Caverns in Virginia's Shenandoah Valley is the Great Stalacpipe Organ, the worlds largest musical instrument.

Stalactites covering 3 1/2 acres of the surrounding caverns produce tones of symphonic quality when electronically tapped by rubber-tipped mallets.

This most unique, one-of-a-kind instrument was invented in 1954 by Mr. LeIand W. Sprinkle of Springfield, Virginia, a mathematician and electronic scientist at the Pentagon.

He began his monumental 3 year project by searching the vast chambers of the caverns selecting stalactites to precisely match a musical scale.

Electronic mallets were wired throughout the caverns and connected to a large four-manual console.

When a key is depressed, a tone occurs as the rubber-tipped plunger strikes the stalactite tuned to concert pitch.

For many years Leland played the Stalacpipe Organ for visitors, as seen in the bottom left photo.

Close-up of one of the mallets which strike a stalactite when an organ key is pressed.