Stones that Hold Secrets
Discovered in the sands of Great Sand Dunes National Park and Preserve, oddly shaped stones play rock music.
When Jack Williams was riding his horse through the west side of Great Sand Dunes National Monument in 1938, his hazel-colored eyes fell on a granite rock shaped like a slender baguette sticking six inches out of the sand.
He dismounted his horse and kicked the stone, expecting it to fall over. It didn’t move. His toes ached inside his boot from striking the heavy object. So, he stood there, digging and pulling on the 25-inch-long stone until all 10 pounds of it fell into his hands. Williams had no idea what the long, narrow polished stone was. But he knew someone had taken great care to sculpt it. He loaded it in his bag, made a mental note that he found it near Big Spring Creek and trotted away.
The national monument was young then, only six years old. But its shifting sands and the surrounding San Luis Valley that spans 8,000 square miles had been home to people for more than 10,000 years. Through the years, people had left traces of their lives like drawings on rocks, spear points in the sand and a number of polished and oblong granite stones like the one Williams found.
It would take 62 more years before the monument became a “national park,” and during that time Williams, who later became a National Park Service employee, donated the artifacts he found, such as the curious stone, to the park’s collection. Others uncovered similar stones in the park, and they, too, ended up in drawers in the park’s collection.
One day, in 1976, Marilyn Martorano, a recent graduate of Alamosa State University and park service volunteer, opened one of the drawers. She was struck by the strangeness of the stones. They were like pestles—a tool used to crush and grind corn and other materials like seeds, nuts, berries and pigment—but heavy and unnecessarily large compared to other pestles. She asked about them.
As it turned out, a handful of theories had been traded around. Maybe they were agricultural tools used to plant corn or chiles. Or giant pestles fashioned to grind food. Perhaps ancient people used the heavy polished stones to smash bison bones. After all, thousands of bison has been roaming the valley for hundreds of years. They were common even as late as the 1800s.
But park officials knew that the oddly shaped stones were predominantly discovered in wetlands or former wetlands. And that made things even more puzzling. The stones’ proximity to water gave rise to the theory that ancient people tied nets to them to try to catch ducks.
The theories, while intriguing, didn’t seem to add up. The stones were awfully heavy to be casting hanging nets in the hope of capturing a duck. And if they were used to grind pinon nuts, which are the size of appleseeds, a two-foot-long stone seemed like overkill. Plus, there were no grinding marks where you’d typically find them.
Further complicating things was many of the stones were found by collectors who didn’t document where they found the stones nor what they found with them. And for archaeologists trying to piece together ancient history, knowing where an artifact was discovered and what was found with it is key. The more pieces of a puzzle you have, the easier it is to see the big picture.
As researchers over the years pulled the stones out of the museum’s drawer and examined them, there was one thing they neglected to do.
They didn’t tap on them.

Forty years passed and Martorano, now a professional archaeologist, returned and opened the drawers in the Great Sand Dunes collection. For years, she remained stumped as to what the polished stones were used for. She borrowed some to study at her office in Longmont, Colo. But the closer she examined them, the more mystified she became.
She needed a crystal ball of sorts to see back into the past. And these days, the closest we have to that might be YouTube, the source of seemingly infinite, instantaneous cross-cultural sharing. On the night before she had to return the stones to the park, a friend sent her a link to a YouTube video.
It changed everything.
French paleo-musicologist Erik Gonthier, a former jeweler and stone-cutter, appeared on her computer screen. He had examined curiously shaped stones brought back to France by French soldiers from the colonies of Algeria and Sudan in the early 1900s. When he tapped on them, he discovered they actually made musical sounds. It was a phenomenally exciting breakthrough.
To showcase ancient peoples’ musical instruments, the French National Orchestra did three concerts in Paris in 2014, playing 24 of the musical stones, also known as “lithophones.”
“That will be their last concert together,” Gonthier of the Natural History Museum in Paris told Agence France-Presses before the shows. “We will never repeat it for ethical reasons – to avoid damaging our cultural heritage. We don’t want to add to the wear of these instruments.”
The video clip ended. Martorano skeptically eyed the stones in her living room. Could they be musical instruments? Her daughter, a percussionist, had a mallet. She picked it up and tapped a stone. A musical sound rang out, shattering the silence blanketing her living room. It was as if the notes had raced through thousands of years to fill the air.
“I was by myself, and it was nighttime,” Martorano recalls. “It made the hair on my arms stand up. I thought, ‘What if no one has heard this sound for thousands of years?’”
She tapped on the other stones. Time seemed to shrink and stretch simultaneously as ancient sounds filled the room. An A sharp note rang out, then a D and an F sharp and G sharp. Each stone produced at least two different sounds. When arranged side-by-side, they resembled a modern marimba, a percussion instrument made from sets of wooden bars. The longer pieces play low notes and the shorter pieces play high notes.
“The 22 artifacts played a minimum of 57 notes, and more than half fit into the pentatonic scale,” she says, noting it’s a scale used by many cultures and notably in the U.S. in country music and jazz. “It’s interesting to me that these rocks have a tonal structure that is used throughout the world.”
Martorano returned the stones the next day, sharing her discovery with Fred Bunch, chief of resource management at Great Sand Dunes National Park and Preserve. His jaw dropped.
“Marilyn thought to tap on them,” Bunch says. “She’s is a great researcher and asked the right questions and saw that lithophones were used in other parts of the world.”
Across the globe, ancient lithophones have been discovered in India, Vietnam, Korea, Japan and beyond. And it’s important to note that not every mysterious shaped rock found is considered a “lithophone.” Anyone who’s ever played with rocks as a kid knows not all rocks make noise. Go for a walk and try tapping on rocks along the sidewalk or trail. Martorano pulls out a piece of sandstone and taps it. It makes a noise, but it’s not a musical note.
“It has to have the right material, shape and density,” she says.
While no one knows for sure if these stones were used to make music or had additional uses, the lithophone theory may be one of the more promising.
Bunch says the park is working with tribes whose ancestors lived or traveled through the San Luis Valley to find out if their oral tradition contains information about the stones.
“It’s premature to say anything,” Bunch says. “We need to learn more. We are in a constant state of discovery. The beauty of this expansive park is that we are learning every day. The more we know, the better managers we can be.”
The stones seem to raise more questions than answers, serving almost as Zen koans, riddles that stun you into thinking but have no answer. Try, for instance, this one: “When both hands are clapped a sound is produced; listen to the sound of one hand clapping.”
What’s for certain is the stones meant something to the people who spent hours sculpting them.
“If you look at these two artifacts here,” Martorano says pointing to two of the stones, “they were supposedly used for cutting and chopping, but I borrowed them and found they made beautiful sounds. We need to open our minds that sound may have been really important to past peoples. How many times do we hear music every day? Perhaps music was just as important in the distant past as it is today.”
She pauses. And then offers a different story than the classic survivalist narratives we’ve all heard about ancient hunter gatherers.
“That ancient people were making music is important because it means ancient people were not just living to survive,” she says. “They wanted meaning in their lives just like we do today, and they were willing to create music in their culture.”