Carole King and the Broadway cast of Beautiful
04/04/2014 at 01:00 PM EDT
All hail the King.
Legendary pop singer-songwriter Carole King may have given producers her blessing to turn her life and songbook into the Broadway musical Beautiful
, but she kept at more than arm's length when it opened for previews last November before its official opening night Jan. 12.
In fact, King refused to see the bona fide box-office hit altogether, citing personal reasons.
But the earth moved under her feet – and the audience's – when King, 72, suddenly stepped out from the wings and onto the stage of the Stephen Sondheim Theatre after Thursday night's performance of Beautiful
Her appearance, during the curtain call, was a surprise to both the cast and the audience. Then she gave everyone an extra treat: a rendition of one of her many signature songs – in this case, "You've Got a Friend."
The show's stage star, King sound-alike Jessie Mueller, accompanied her in the anthem.
"It was an honor to see Beautiful
for the first time last night," King said in a statement afterward. "Jessie Mueller and company are fantastic, and it was so joyous to be there. I couldn't be more proud."
Why had King stayed away for so long? Reportedly, the stage bio dredged up too many painful memories for her, despite its covering such triumphs as the song hits "One Fine Day" and "Will You Love Me Tomorrow," as well as her landmark 1971 solo album, Tapestry
, which sold more than 25 million copies worldwide.
Personally, the story follows her from precocious young musician in New York through her troubled relationship with collaborator and, eventually, husband (and then ex-husband) Gerry Goffin.
"I already went through this. It's very painful to live through it again," King had told Playbill.com.
at the time the show was coming together.
King's daughter and manager, Sherry Kondor, said her mother actually walked out halfway through the reading. "She said, 'I have to go. I can tell it's great, but I can't watch my life played out before me.' "
King's surprise appearance Thursday was, in fact, for a good cause – to help raise money for Broadway Cares/Equity Fights AIDS
"I was thrilled to help the cast raise a fast $30,000," King said. To paraphrase one of her songs, she's into something good.
Additional reporting by STEPHEN M. SILVERMAN