As he took her into his dungeon with a fire torch  they made an eye contact
As the song began to play then elsa started singing

Elsa
In sleep he sang to me
In dreams he came
That voice which
Calls to me
And speaks my name

And do I dream again
For now I found
The Phantom of the opera
Is there, inside my mind

As the instrument got lower
He began to  sing

Ninja
Sing once again with me
Our strange duet
My power over you
Grows stronger yet

And though you turn from me
To glance behind
The Phantom of the opera  is there
Inside your mind

As he took her down the stairs and saw  a black horse  she ride on it as he was walking with the horse while elsa was riding on it

Elsa
Those who have seen
Your face
Draw back in
Fear
I am the mask
You wear

Ninja
Its me they hear

Ninja & Elsa
My spirit and my voice
In one combined

Ninja & Elsa
The Phantom of the opera
Is there inside your mind

As they finally reach the boat He helped her down the horse  as he took her there she step into the boat sitting
As he pushed the boat with the stick

Back up
Beware the phantom of the opera

Elsa
He's there the phantom of the opera

As the gates open by itself a pair of candles appear as elsa look at him she has no choice but to sing for him

Ninja
Sing my angel muse

Elsa's voice was  high as he was still plading in their destination

Ninja
Sing my angel

Elsa voice got higher as he was still plading  while looking at her

Ninja
Sing  for me

Elsa's voice was higher

Ninja
Sing

She continued her the most highest note

Ninja
Sing my angel
Sing For Me!

As elsa sings the most highest note they finally reached the end of the boat