I've Been Working on the Railroad
"I've Been Working on the Railroad" was an old American folk song. It was sung three times by The Doctor in 2376 on board of the . He sang the first verse while treating a group of injured Qomar. 

It was the first piece of music they had ever heard and they were intensely fascinated and intrigued by it. He amused them further by singing the fourth and fifth verse of the song. 

After his short-lived fame on the Qomar homeworld ended disappointingly, The Doctor was so upset about it that he wanted to delete all his musical subroutines, but Captain Janeway prevented him from doing so. He was cheered up by Seven of Nine when she gave him a piece of fan mail in which she declared that she would always be his loyal fan. Feeling better he began singing the first verse of the song to himself. ()

Selected lyrics 
I've been working on the railroad
All the livelong day
I've been working on the railroad
Just to pass the time away

Can't you hear the whistle blowing
Rise up so early in the morn

[...]

Someone's in the kitchen with 
Someone's in the kitchen I kno-o-o-ow
Someone's in the kitchen with Dinah
Strummin' on the old banjo!

Singin' fi, fie, fiddly-i-o
Fi, fie, fiddly-i-o-o-o-o
Fi, fie, fiddly-i-o
Strummin' on the old banjo

External link 
 
de:I've Been Working on the Railroad
Earth musical compositions