Bardic Madness XX, which featured challenges on circles, cycles, returning, and remembrance, simply demanded a class on rounds, so I stepped up with Let the Catch Go Round: Canons, Catches, and Circular Songs. The subtitle tells it all.
Though the heyday of published rounds is slightly post-period, there is enough documentary evidence to make a pretty healthy list of period rounds. Sumer is icumen in is probably the most celebrated round of the era, but Three blinde mice and Hey, ho, nobody home were published in 1609, and were likely sung well before that date.
Though many 17th-18th century rounds were written for men's clubs. the Victorians turned rounds into a children's format. They should be for everybody, and I hope to hear more rounds at our bardic circles in the future.