In 1949, researchers testing underwater acoustics off Bermuda lowered an early recording system into the water and kept the unexplained sounds it picked up. Seventy-seven years later they were identified as what may be the oldest preserved recording of a - Space Daily

A mysterious sound recorded in 1949 remained unidentified for 77 years—until scientists realized they'd captured the oldest known whale song, decades before anyone understood these creatures sang at all.