[Galadriel55]

Is it Thorondor?

When light and hope are long forgotten
Behind closed doors, in deep dungeons and chains of iron,

Everything to do with Thangorodrim

Only I can find a way
Over the mountains or under wide waters and even to the highest tower

This is true, unless Elves, Men, and Dwarves can somehow grow wings

To come and bring back
Friend to friend, lover to lover and kinsman to kinsman,

Fingon and Maedhros, Beren and Luthien, ...Hurin and Huor?

Allowing the tortured souls
To give voice one last time before they are released.

Now that's still a bit puzzling...