By Trey Songz, although an actor lip syncs the recording in episode, 8, I believe it is.
Excellent mini series that was cancelled after the first couple of episodes of the second season, earlier this year. The complete first season is available as a box set and I do recommend it as I found it to be very entertaining. Trey Songz does an amazing rendition of the song by Bowie. It's on youtube. Both the excerpt from the episode and one taken straight from the original recording.

Here's a link to the excerpt
https://www.youtube.com/watch?v=9ZsrvDVGFIE

David Bowie is surely missed, I'm rather despondent that there is no ''More Bowie" anymore.