在元代北方中原一帶的實際語言中尚有入聲,元曲作家為"廣其押韻",將當時北方中原一帶實際語言中的入聲派入平、上、去三聲,而《中原音韻》是"為作詞而設",故其"入派三聲"是依據元代曲家的曲作語言,而不是實際語言。"入派三聲"實是為便于演唱,因入聲字急促而不響亮,與悠長響亮的腔格不合。北曲南移后,因南方方言也有入聲,故周德清編撰《中原音韻》,以前輩曲家的"入派三聲",給當時的北曲作家提供借鑒,來規范北曲入聲韻的使用。

There was entering tone used in daily language in North-Central China in the Yuan Dynasty.In order to extend the rhymes of yuanqu,playwrights integrated entering tone into the other three tones,respectively the level tone,the falling-rising tone and the falling tone.The Tones and Rhymes in North-Central China was a reference book "compiled for playwriting",so the "integration of entering tone into the other three tones" referred to the language used by yuanqu playwrights in scripts rather than that in daily life.Such integration was designed for the convenience of singing,for the words with entering tone were uttered fast and could not be pronounced loudly,which was out of kilter with the slow-tempo and sonorous singing.Later,yuanqu in North-Central China was introduced to the Southern Jiangnan region and flourished there.Because there was entering tone in the Jiangnan dialects,ZHOU Deqing compiled The Tones and Rhymes in North-Central China to provide reference and to standardize the use of entering tone in rhyming for the North yuanqu playwrights.