Sijo poetry originated during the Yi dynasty of Korea (from 1392) and was an important development which remains popular to this day. Sijo are composed of three lines, each with approximately fifteen syllables and each with a pause midway through each line. Modern sijo are often presented as six line poems, with the midway pause determining the end of each line. Originally the sijo were sung and were a popular diversion for the upper classes.

• http://search.eb.com/eb/article?query=&ct=&eu=109589&tocid=61957#61957.toc
• http://members.tripod.com/~Startag/AboutSijo.html
• http://www.korea.net/directory/List.asp?Category_id=a0100202
  (directs you to sites on sijo)