The vocoder was invented to improve telecommunications in the 1930s and re-purposed by the military to mask speech among officials during World War II. By the 1980s, artists like Afrika Bambaataa and Zapp began using it as a musical instrument. The sound caught on and has remained one of the most influential movements in music to this day, although Auto-Tune (not included on the list), has mostly replaced it.
Writer Dave Tompkins is somewhat of a vocoder historian; the legendary music journalist wrote a book this year, How To Wreck A Nice Beach, chronicling the machine's history. (The book includes a chapter on Talkbox, vocoder's funkier twin sister, which explains its inclusion on parts of the list.) Musicians have been trying to sound like robots for years, and this Tompkins-curated list of The 50 Greatest Vocoder Songs is the ultimate guide to the machine's best moments.