The Mystery of the Singing Sand Dunes- Solved?

It's been a mystery that has been observed in deserts around the world, and has been noted by travelers including Marco Polo: the low thrumming sound that large sand dunes make, known as The Singing Sands.

Now, a team of engineers may have solved the mystery: according to them, the interaction between sliding sand on large dunes and the hard-packed cores set up a standing wave that makes the sounds. As this video shows, they picked an interesting experimental style to demonstrate the phenomenon: