I haven't been following this, but I gave the album a listen today. I didn't know it was just a cover album. When Lady GaGa said "Jazz Revival", I thought I was about to listen to some innovative new Jazz sound. There isn't really anything interesting or special about the album. They didn't really add anything to the already great Jazz songs. It would've at least been a good cover album if they tried to revamp the songs and make them sound fresh, but this sounds like it was released 1930's, and that isn't a good thing. They should be trying to move the Jazz genre forward, and they are acting as if they are, but any regular cabaret singer could've done this just as well or better.
