This song is from the "Disney Jr.'s Ariel" season 1 finale "The Glow Crystals", and has Ariel expressing frustration at being unable to figure out a crystal puzzle to save Triton, Ursula, Sebastian and Flounder.
I'm missing a puzzle piece
I'm not gonna quit
I'll try "open sesame"
Well, that wasn't it
We followed the clues
I'm getting confused
I thought all the crystals were making it clear
In all of the sea
There must be a key
So what am I looking for here?
I've got to bring my family home
Crack the wall down, crack the code
Rack my brain 'cause we're so close
I need to know
What is the missing piece?
What is the missing piece?
Hmm
What is the missing piece?
What is the missing piece?
There's Fernie's pin
Lucia's wand
Flounder's spoon
The answer's here
I know there's gotta
Be a way
To get them out
To set them free
To hurry up and break it down
What is the missing piece?
What is the missing piece?
Whoa, what could it be?
What is the missing piece?
What is the missing piece?