1. They had never performed together, let alone this song. 2. Bowie wasn't performing it in his set at the time. 3. Queen spent three days rehearsing and putting together the tightest set possible for their twenty minute time slot. read more
Also, Bowie didn’t want to perform the song at that time, even on his own concerts (which he will, eventually), so that wouldn’t work either way. read more
Live performances. Although very much a joint project, only Queen incorporated the song into their live shows at the time. Bowie chose not to perform the song before an audience until the 1992 Freddie Mercury Tribute Concert, when he and Annie Lennox sang it as a duet (backed by the surviving Queen members). read more
In 1981, Queen invited David Bowie to Mountain Studios in Switzerland to sing back-up vocals on their new song "Cool Cat." They weren't satisfied with the results, but Bowie and the four members of Queen started jamming that day and the result was "Under Pressure." The song became a massive hit all over the world. read more