The original "Nightingale" was Jenny Lind. 

In the middle 1800s, Jenny Lind was a Swedish singer that wowed the world.  She was the Britney Spears of her day.  She toured the United States in 1850-1852 and was called "The Swedish Nightingale". 

She may have been the first modern "pop" singer. 

This is my site about song.