Story highlights Ryan Gosling had nothing but praise for his "La La Land" costar Emma Stone at the Los Angeles premiere of the film

"I thought I knew they were there, but I didn't see them in full bloom until we shot the film," he said

"La La Land" opens December 9

Los Angeles (CNN) Much has already been said of Ryan Gosling and Emma Stone's impressive turn in the ambitious and whimsical modern musical "La La Land," a film that's garnering significant praise heading into award season -- from the actor's electric chemistry to their arduous months-long preparation for the roles Sebastian and Mia.

But arguably, no one was left more in awe of what was accomplished than Gosling. Despite working with Stone twice before -- in 2011's "Crazy, Stupid, Love" and 2013's "Gangster Squad" -- the actor told CNN at Tuesday's Los Angeles premiere that Stone still found a way to surprise him with her skills.

"She shows so many of her talents in this film," he said. "I thought I knew they were there, but I didn't see them in full bloom until we shot the film."

One of Stone's shining moments in the film involves her character, an actress, attending a terrifying and vulnerable audition that could make or break her future. In the climactic scene, Stone performs a hauntingly beautiful tune that Stone admits was a tough one to get through.

"It was just a little overwhelming but in a great way," Stone said.

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