Lithophones, or stone bells, were one of my discoveries on my visit to Lalibela, Ethiopia.

Until then, I had been vaguely aware that jade bars had been used as chimes or bells in ancient China, but I did not know that stone bells were used in Ethiopia.

Of the lithophones I saw in Ethiopia, this set at the Monastery of Na’akuto La’ab near Lalibela was the best engineered, supported as they were from a relatively horizontal piece of wood that was, in turn, held by forked tree limbs or tree trunks sunk into the ground.

My background in archaeology, where I found and examined many types of lithics, aka rocks, tells me the bells are made of flint, chert, or some other rock with similar properties.

How do I know this? It's the tell-tale blue of the rock's interior below its weathered skin, and the shape of fractures that have the rock's interior. That's just what flint and chert look and behave like.

With that, I've told you all I know about this musical instrument. What don't I know?

> What it sounds like.

> How far the sound carries.

> How sound is produced, though there's a round, black object resting on the top bell that could be the clapper.

> How old the bells are.

> What is the bells' history? Have they always been at this monastery, or have they been in other places?

> On what occasions the bells are used.

> How often the bells are used.

> There are two bells. Is any attempt made to produce a carillon effect (albeit a limited one) or a tune by ringing both bells in a predetermined order and rhythm?

> Do any other musical instruments ever accompany the bells?

> Are new lithophones still being made in Ethiopia? If so, by whom?

> Can anyone strike the bells, or is that task assigned on the basis of status or seniority?

> How important is the spacing between the bells, between the bells and the ground, and between the bells and the wall?

> How often are the cords that support the bells examined for soundness, and how often are they replaced? Ditto for the wooden supports.

Well, I'll be sure to get answers to all these questions the very next time I'm at the Monastery of Na’akuto La’ab.