What is the meaning of song?

noun

• A short musical composition with words.
  • usage: "a successful musical must have at least three good songs"
  • synonyms: vocal
• A distinctive or characteristic sound.
  • usage: "the song of bullets was in the air"; "the song of the wind"; "the wheels sang their song as the train rocketed ahead"
• The act of singing.
  • usage: "with a shout and a song they marched up to the gates"
  • synonyms: strain
• The characteristic sound produced by a bird.
  • usage: "a bird will not learn its song unless it hears it at an early age"
  • synonyms: birdcall, call, birdsong
• A very small sum.
  • usage: "he bought it for a song"
• The imperial dynasty of China from 960 to 1279; noted for art and literature and philosophy.
  • synonyms: Sung, Sung dynasty, Song dynasty