As pointed out, this question will be relevant only if you are be referring to the Ci 詞 form, prevalent in the Song 宋 dynasty, which is traditionally sung by courtesans. Strictly speaking, this will not be 'new material'; nonetheless, modern songs do use the form occasionally. An example will be the Nian4 Nu2 Jiao1 by Su1 Shi4:
《念奴嬌》 蘇軾
大江東去,浪淘盡,千古風流人物。
故壘西邊,人道是,三國周郎赤壁。
亂石崩雲,驚濤裂岸,捲起千堆雪。
江山如畫,一時多少豪傑。
遙想公瑾當年,小喬出嫁了,雄姿英發。
羽扇綸巾,談笑間,強虜飛灰湮滅。
故國神遊,多情應笑我,早生華髮。
人間如夢,一尊還酹江月。
The format for such literary form are usually given by the Ci2pu3 詞譜 or lyric score, which defines the number of letters in each phrase, the intonation of each letter, and where the rhyme should land. Nian4 Nu2 Jiao1 is the name of the song, or Ci2 Pai2 詞牌. Different songs will usually demand different phrasing, rhyming and intonation strategies, just as we do in song writing today. So, the Nian4 Nu2 Jiao1 format above, as given by the Bai2xiang1 ci2pu3《白香詞譜》will go like this:
八七、念奴嬌·石頭城 薩都拉(用東坡赤壁韻)
石頭城上,
●○○●
望天低、
●○○
吳楚眼空無物。
⊙●●○○▲
指點六朝形勝地,
⊙●⊙○○●●
惟有青山如壁。
⊙●⊙○○▲
蔽日旌旗,
⊙●○○
連雲檣櫓,
○○⊙●
白骨紛如雪。
⊙●○○▲
一江南北,
⊙○○●
消磨多少豪傑。
⊙○⊙●○▲
寂寞避暑離宮,
⊙●⊙●○○
東風輦路,
○○⊙●
芳草年年發。
⊙●○○▲
落日無人松徑冷,
⊙●⊙○○●●
鬼火高低明滅。
⊙●⊙○○▲
歌舞尊前,
⊙●○○
繁華鏡里,
⊙○⊙●
暗換青青發。
⊙●○○▲
傷心千古,
⊙○○●
秦淮一片明月。
⊙○○●○▲
Each symbol corresponds to a letter. ▲ indicates where the rhyme lands while ●○⊙ indicates the intonation. Note the similarity in phrasing to the song quoted above.
The Ci2 is also known as the 長短句, or long-short verse, due to the varying number of letters in each phrase, as contrasted with the Shi1 詩, which is usually of uniform meter (such as the pentametric poem or 五言詩).