Incredibly, due to a musicians’ strike at the time, Dooley Wilson NEVER RECORDED IT. He didn’t play the piano in the film, either! A drummer and vocalist, his piano-playing was done by a pianist, just off-camera.
Because of the strike (which lasted for TWO YEARS, with some companies) Warner released an earlier version by another vocalist – and by the time it ended, the window was GONE.
Only when Woody Allen revived interest in “Casablanca” (and other Bogart movies) in his movie, “Play It Again, Sam” (1972) did interest in the number return.
Unfortunately, since Dooley had been dead for twenty years by then, the only thing that could be released was a single that compiled audio-clips from the movie.
So Dooley Wilson’s “As Time Goes By” remains the massive hit that NEVER WAS, covered by everyone – except the man who made it famous.