Will Smith says that he improvised the fan-favorite piano scene from the 'Fresh Prince of Bel-Air' pilot

• Will Smith said he improvised his character's piano moment in the "Fresh Prince of Bel-Air" pilot.
• Smith said that he was originally supposed to sit at the bench and reflect on his uncle's words.

Will Smith said that he improvised a beloved scene from the series premiere of his hit '90s sitcom "The Fresh Prince of Bel-Air."

The 1990 pilot of "Fresh Prince" centered on Smith's character having a fish-out-of-water experience as he left his hometown of West Philadelphia to live with his Uncle Phil (James Avery), Aunt Viv (Janet Hubert), and three cousins in their lavish Bel-Air mansion.

The episode showed Will's lack of decorum, bold fashion sense, and constant use of slang like "dope" - all of which contrasted with the posh lifestyle of the Banks family. At the end of the episode, Uncle Phil scolded Will for making a spectacle of himself at an elegant dinner.

After exchanging terse words, Uncle Phil told Will, "Before you criticize somebody, you find out what he's all about." Then he dismissed Will's attempt to share his side of the story, saying that he knew exactly what his nephew was about.

Uncle Phil was proven wrong though as Will went over to the piano and unexpectedly began playing the classic Beethoven tune "Für Elise." The surprising moment caused Uncle Phil to pop back into the living room and smile as he listened.

In chapter three of his self-titled memoir, released on Tuesday, Smith said that when he filmed the pilot, he was originally supposed to sit at the bench and look pensive. But he went off-script and the moment ended up illustrating that Uncle Phil misjudged Will.

"The producers had originally planned on me sitting with my back to the piano so they could push the camera in on my face as I pondered the profundity of Uncle Phil's closing words," Smith wrote. "But when I sat down, I faced the piano, and began playing Mom-Mom's favorite, Beethoven's 'Für Elise.'"

Unbeknownst to the cast and crew, Smith had previously taken piano lessons because his mother, Carolyn Bright, played and it "was the only instrument that actually liked me."

The actor said that Avery was "stunned," and "stepped back around the corner."

"The set went silent as everyone realized this show was about to be special," Smith recalled. "The point of the scene had been to never judge a book by its cover. The producers were so inspired by this improvisational moment that they kept it, and it became the defining thematic premise of the entire series."

NBC's "The Fresh Prince of Bel-Air," also starring Alfonso Ribeiro, Tatyana Ali, and Karyn Parsons aired for six seasons before going off the air in 1996.