For a song 意為「廉價地，非常便宜地」，通常與 go、buy 和 sell 等動詞連用。它從 1500 年代末期開始使用至今，英國劇作家莎士比亞在他的戲劇《終成眷屬》(All’s Well That Ends Well) 中就使用了這個慣用語。這一喜劇首次出版於 1623 年。All is well that ends well 字面的意思是「結局好，一切都好」。
例句：
- I bought this car for a song. (我以非常便宜的價格買了這部車)
- My mother bought the bed for a song at an auction. (我媽媽在拍賣會上以非常便宜的價格買了這張床)
- Because the shopping mall’s closing down, most of the stock is going for a song. (這家賣場要關門了，所以大多數存貨都廉價出售)
- She was wearing a beautiful hat which she’d picked up for a song in the night market. (她戴著一頂在夜市廉價購買的漂亮帽子)