Today we’re learning more about Mrs. Weasley’s favorite jazz singer, Celestina Warbeck, who currently performs at The Wizarding World of Harry Potter’s Diagon Alley expansion.

Rowling released a biography about the popular witch singer on Pottermore Monday morning and debuted a studio recording of one of the songs Celestina performs at Diagon Alley.

The author writes on her website, “Celestina is one of my favourite ‘off-stage’ characters in the whole series, and has been part of the Potter world ever since its inception, making an early appearance in the short-lived ‘Daily Prophet’ series I produced for members of the equally short-lived fan club run by my British publisher, Bloomsbury. Although we never lay eyes on Celestina during the whole seven volumes of the Potter books, I always imagined her to resemble Shirley Bassey in both looks and style. I stole her first name from a friend with whom I worked, years ago, at Amnesty International’s Headquarters in London; ‘Celestina’ was simply begging to be scooped up and attached to a glamorous witch.”

Rowling says that today, August 18, is Celestina’s birthday.

By visiting Pottermore you can check out the studio version of “You Stole My Cauldron But You Can’t Have My Heart” by Celestina and learn about the singer’s history.

Though Rowling didn’t write the lyrics to the song, she did come up with the title and then let the theme park write their own jazz tune.

Alternatively, you can watch this live performance from Universal Orlando’s Diagon Alley:

This latest entry on Pottermore is an interesting bit of synergy between Rowling’s Potter properties. Celestina has only been brought up within the fan community in recent weeks thanks to Diagon Alley, and now she’s sharing more about the singer on another arm of her Potter empire.

By the way: We were unaware of this “Daily Prophet series” Rowling says she ran for Bloomsbury so we found some interesting info on the HP Lexicon.