汉语填词所依据的曲调名称，称词牌名或词调。宋代以前的词都是配合音乐歌唱的，有的依调填词，
有的依词制调，曲调乐谱的名称即是词牌。填词既要求合乎音乐腔调，又要合乎一定的格律
（即词律），如字数、平仄、句式、韵位等。宋代以后主要是依调填词，且大多数词人只懂格律，
不懂音乐，他们只是按照格律填词，所作词走上了与音乐脱离的道路。明代以后，宋词曲谱大抵失传，而按照格律填词却继续不断，词牌名只作为文字、
音乐的结构的定式，词也成为一种独立的诗歌形式了。
词牌种类繁多，总共在1000个以上，其中常用的大约只有100多个。
Chinese lyrics are based on the name of the tune, saying the tune name or word transfer. Song with the music before the words are singing, and some lyrics by tone,
Some transfer system according to the word, the name of that tune is tune music. Lyrics to demand a cost-tone music, but also in line with some metrical
(That word law), such as the number of words, tones of the words, sentences, rhyme are found. After the transfer is mainly by Song lyrics, and most people only know the word rhyme,
Do not know music, they are only in accordance with the metrical lyrics, the lyrics and music out onto the road. After the Ming Dynasty, Song scores probably lost, but has continued in accordance with metrical lyrics, tune name only as text,
The structure of the fixed-style music, the word has also become an independent form of poetry.
Tune a wide range, a total of more than 1,000, of which only about 100 commonly used.