Musical instruments have been around for at least 37,000 years in countless types, varieties, and classifications, all with one goal: creating sound waves. And yet most instruments have remained relatively unchanged throughout their histories; in fact, painstaking efforts are often taken to make sure machines are built to centuries-old specifications.

But some do eschew conventional processes to create truly unique sonic experiences. Organs that harness the tide or are built from stalactites, a secret Lullaby Factory, and a bass that plays notes so low humans can’t hear them exemplify an even wider scope of musical innovation. Here are 19 of the most wonderfully unusual instruments around the globe.