Ancient poetry music can be used to sing. So it's called poetry. The biggest difference between poetry and writing is the difference in meter. Poetry pays attention to the neatness of antithesis and the unity of writing. Or seven words or five laws. Ci, on the other hand, has a fixed format, which rose after the Tang Dynasty. It is distinguished according to the different names of tablets.
Yuanqu is a drama of the Yuan Dynasty. Because the imperial court was full of Mongols at that time, the Khan culture was restricted, and the literati could only change the old rules and form new problems. So it is called Yuanqu, but it hasn't changed.