Scientists first started mapping out the structure of humpback whale songs in the 1960s, after underwater microphones designed to record Soviet submarine signals picked up their otherworldly music. By 1971, they had developed a hierarchical notation system, dividing whale vocalizations into units, phrases, themes, and full songs. 

According to Medium, humpback whale songs, which can last for up to 23 hours, are sung synchronously by populations of whales spread out across thousands of miles. Individual whale populations have their own songs and dialects; over time, their songs evolve spontaneously, in much the same way language does. 

But though we know whale songs are more than random clicks and groans, it can be difficult to hear the sound patterns and repeated themes that make whale music so unique. In part, that’s because whale music is so slow—the pacing makes it tough for human ears to pick up the patterns in the prolonged sounds. But it’s also because whale songs are much freer in form than the music we create.

In order to make the patterns and repetitions in whale songs easier to understand, musician David Rothenberg teamed up with data visualization designer Mike Deal to create a standardized system of graphic notation. Together, they translated different whale sounds into specific shapes and colors. The duo then charted these symbols out on sheet music, aligning each shape with lines on the staff. While the symbols don’t line up with strict pitches or rhythms, they give a sense of the musicality of whale songs: notes are repeated, themes are formed, and suddenly the alien wails of a mysterious animal become a song. Check out an example of the notation system in action below: 

[h/t: Medium]