TropicalCola

I don't think this is the case like Gatsby was. Because there's also lots of Danny Elfman's music... Well but I'm not 100% sure, you can be right, too. I guess everything's possible (it's Lana + Burton after all).

Oh yes, sorry my fault. Edited

What I know from my sources, "Big Eyes" plays somewhere in the middle of the movie and "I Can Fly" will play during the motion credits in the end.

I think her voice is sort of similiar to Lana's when she sings deep notes For example in MØ's song collaborated with Avicii, lots of people thought that it's Lana singing it. (Sorry don't know how to add video) https://www.youtube.com/watch?list=UU8xmjTfSP4reB6ZS7K-OGMg&v=MfeZG6K1JRw&feature=player_detailpage#t=61