Singing in Tribulation
Confessing when put to the torture. Such a person is termed in goal slang a “canary bird.”
“ `This man, sir, is condemned to the galleys for being a
canary-bird.' `A canary-bird!' exclaimed the knight. `Yes, sir,'
added the arch-thief; `I mean that he is very famous for his singing,'
`What!' said Don Quixote: `are people to be sent to the galleys for
singing?' `Marry, that they are,' answered the slave; `for there is
nothing more dangerous than singing in tribulation.' ” —
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Singing in Tribulation from Infoplease: