what songs do monsters sing.

In my learned experience, ogres listen to Slayer, orcs listen to early Metallica, hobgoblins dig Megadeth, and elves listen to Celine Dion.

Oh, and kobolds listen to Nickleback.

Goblins in Pathfinder are noteworthy singers, and several adventures print some of their songs.

Mr Tabaxi
You ought to ask Mage Misty Cough
The original conjuring tabaxi
Please, listen to me...
And don't scoff
All his inventions are of his own bat
There's no such tabaxi
In the waterdeep
He holds all the Cat Nip monopolies
For performing surprising illusions
And creating eccentric confusions
The greatest magicians have something to learn
From Mage Misty Cough's conjuring turn
And we all say
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
He is quiet and small, he is black
From the ears to the tip of his tail
He can creep through the tiniest crack
He can walk on the narrowest rail
He can pick any card from a pack
He is equally cunning with dice
He is always deceiving you into believing
That he's only hunting for wererats
He can play any trick on an adventurer
Or a spook a rogue out his hiding place
If you look for your sword or plate
And you think it was merely misplaced
You have seen it one moment
And then it is gone
But you find it next week
Lying out on the lawn
And you'll all say
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
"Presto!"
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
His manner is vague and aloof
You would think there was nobody shyer
But his voice has been heard on the roof
When he was curled up by the fire
And he's sometimes been heard by the fire
When he was about on the roof
At least we all heard that somebody purred
Which is uncontestable proof
Of his singular magical powers
And I've known the family to call
Him in from the garden for hours
When he was asleep in the hall
And we'll all say
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
"Oh, well I never, was there ever
A tabaxi so clever as magical
Mage Misty Cough"
Ladies and gentlemen
I give you the magical, Marvelous Mage Misty Cough

Acererak’s Tomb
It’s creepy and It’s kooky, mysterious and spooky
It’s all together ooky, the Acererak’s Tomb
His Crypt is a museum, when people come to die in
They really are a scre-um the Acererak’s Tomb
Neat, sweet, pee you!
So get a death save on, a dungeon you can crawl in
We're going to make a call on the Acererak’s Tomb
It’s creepy and It’s kooky, mysterious and spooky
It’s all together ooky, the Acererak’s Tomb
His Crypt is a museum, when people come to die in
They really are a scre-um the Acererak’s Tomb
Neat, sweet, pee you!
So get a death save on, a dungeon you can crawl in
We're going to make a call on the Acererak’s Tomb

Vampire Nerds
Clap your hands everybody, and everybody clap your hands!
We're Vampire Vampire Vampire and... Mind Flayers
We come here on stage tonight to do a show for you
We've got a rockin looks and a high gothic sound
That'll make you move your body down to the ground
We've got Pandora on the violin
And Lestat and Gabrielle will be joinin' in
We've got Dracula on a mean guitar
And a rap by little old me Strahd Von Zarovich
We've got Thuringwethil beating on his gong
The boys and the Minds's are clapping along
And just when you thought you'd seen it all
Along comes a Vampire 4 ft tall!
So won't you come on out here, on the floor,
so we can work our bodies like never before
Break!