When I was in high school I had two musical obsessions: David Bowie and Queen. As luck would have it they recorded a song together. The song was never performed live by all members of Queen and Bowie. The closest it ever got was at the Freddie Mercury Tribute concert. Bowie joined the surviving members of Queen and Annie Lennox (doing Freddie's part). You can watch that video on YouTube. I don't care for it. I really don't like hearing Freddie's songs without Freddie's voice.
At some point along the way someone re-mixed the song to put together live performances from Queen and David Bowie.