If toi were to have a duet with with your favori singer, which song would the two of toi sing?

I'd l’amour to do a duet with Idina Menzel! She's my favori Broadway actress and singer, and one of the most inspirational women I've ever seen.
I'm a massive fan of symphonic metal bands like Within Temptation, and I think her powerful voice would fit perfectly. I chose the song from above because it's already a duet.