The musical "Beautiful" focuses on the early life of Carole King and has been playing packed house to packed house in New York--Carole King herself has never seen a performance, until that changed last Thursday.

The well-respected pop singer-songwriter finally attended a show and gave the crowd a shock when she made her debut appearance at the curtain call, reports Fox News.

King has avoided seeing the box-office hit due to extremely personal reasons. The material covered in the musical deals with her marriage to Gerry Goffin falling apart, making it too difficult for King to watch.

“I already went through this. It’s very painful to live through it again,” King told Playbill.com. Her personal manager and daughter, Sherry Kondor, even confessed that Carole King left during the first reading.

"It was an honor to see Beautiful for the first time last night," said King. "Jessie Mueller and company are fantastic, and it was so joyous to be there. I couldn't be more proud."

Carole King waltzed up to the stage and performed one of her classic songs, "You've Got a Friend," during the time the cast was on collecting money give to the charity, Broadway Cares/Equity Fights, according to Playbill.com. The performance was a tear jerking for many in the crowd and cast, especially Jessie Meuller, who acts as King in the musical.

Watch the video below to see King surprise the cast on stage: