(CNN) -- For one private collector, it's the beginning of a beautiful friendship.
A buyer has purchased the piano used in one of the most beloved scenes in all of film: the playing of "As Time Goes By" in "Casablanca" -- the 1942 classic movie starring Humphrey Bogart and Ingrid Bergman.
Sotheby's New York auctioned the piano for $602,500 on Friday, a sale price lower than expected. The estimated price for the piano had been $800,000 to $1.2 million.
The 58-key piano is a memorable part of the romantic flashback sequence in Paris at La Belle Aurore, where Rick (Bogart) and Ilsa (Bergman) listen to Sam (Dooley Wilson) sing and play "As Time Goes By."
The piano is distinctive for its diminutive size and distinct hue. "Seeing the piano in real life you end up with a couple of things," said David Redden, vice chairman at Sotheby's.
"It's quite colorful, green and distressed yellow. And you don't realize how small it is, so small in fact Bogart and Bergman sort of tower over it."
Redden is no stranger to this famous Hollywood prop. He first auctioned it off back in 1988. "It was sold to a Japanese man and now it's come back to us," Redden told CNN. "He paid $154,000 for it."
On Friday, a pianist played "As Time Goes By" in the Sotheby's salesroom "before the piano was spun around on the turnstile to an awaiting audience and bought by a private collector," the auction house said.
The sale was greeted by applause, Sotheby's said.
The instrument had no significant value in the golden age of moviemaking, Redden added. "It would be re-used again and again," he said.
Many critics and movie-lovers regard "Casablanca" as one of the greatest films ever made. Directed by Michael Curtiz, it won three Oscars, and is replete with memorable lines and scenes.
"The piano is a star of the film," Redden said. "The music is so emotive, so moving and the piano really becomes a symbol of the love story between Bogart and Bergman."
Wilson, the actor who portrayed Sam, was a trumpeter, not a pianist, according to Redden.
"He is sort of miming the fingering. But someone else is playing nearby and he was following the real player," Redden said.
Now, the unknown new owner -- just a "citizen of the world," like the character Rick -- gets to tickle the ivories as time goes by.