The rehearsal footage from a 1992 Freddie Mercury tribute concert shows Michael performing 'Somebody to Love'.
About three minutes in, the camera cuts to Bowie, who is standing to the side of stage nodding in time to the music, in obvious admiration of Michael.
In another video, Michael can be seen singing along to Bowie's duet of 'Under Pressure' with Annie Lennox.
The tribute show was held at London's Wembley Stadium in April 1992, raising funds for AIDS Awareness.
Along with Michael, Bowie and Lennox, stars like Seal, Elton John, Axl Rose and Liza Minnelli performed Queen songs accompanied by the remaining members of the band.