What is song and art song (either in english and chinese)

An art song is a vocal music composition, usually written for one singer with piano or orchestral accompaniment. By extension, the term "art song" is used to refer to the genre of such songs. Aficionados of the genre consider art songs to be among the highest forms of art, unsurpassed in sophistication, subtlety and dramatic truth.
Although categorizing a piece of vocal music as art song rather than as another type of song (such as a folk song, or an aria) can be difficult sometimes, most art songs are

settings of lyric poetry
not part of a staged work (such as an opera or a musical)
intended for performance as part of a recital or other relatively formal social occasion
Although piano accompaniment is usual, the singer may be accompanied by instrumental forces of any number, including a full orchestra. A guitar, a harp or a string quartet are some of the more common accompaniments. Songs may be written to be performed in a group to form a narrative or dramatic whole, comprising a song cycle.
An art song can be in any language, although English songs, French chansons, German lieder, Spanish canciones or canciones lricas, and Italian canzoni are the most numerous. The Austrian composer Franz Schubert is considered the greatest art song composer of all. Despite a brief life, Schubert created an impressive output of some 600 lieder, including "Der Erlknig", "Die Forelle", and "Gretchen am Spinnrade" as well as the two cycles, "Winterreise" and "Die schne Mllerin".
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A song is a musical composition. Songs contain vocal parts that are performed, 'sung,' and generally feature words (lyrics), commonly followed by other musical instruments (exceptions would be acappella songs). The words of songs are typically of a poetic, rhyming nature, although they may be religious verses or free prose. The words are the lyrics.
Songs are typically for a solo singer, though there may also be a duet, trio, or more voices .