According to the press release from Pottermore:
The 500-word entry about Celestina, who is sometimes known as the “singing sorceress,” provides never-before-known facts about this obscure character whom readers never “meet” in the Harry Potter series although she is mentioned several times and
is Molly Weasley’s favourite singer. Pottermore.com also posted today the audio track of one of Celestina’s songs, “You Stole
My Cauldron But You Can’t Have My Heart.” The song is a recording by Universal Orlando Resort featuring Celestina Warbeck and the Banshees who perform live every day at the brand-new, spectacularly themed environment, The Wizarding World of Harry Potter – Diagon Alley. “You Stole My Cauldron But You Can’t Have My Heart” is the first song ever posted on pottermore.com.
The new writing by J.K. Rowling offers colourful new details about Celestina’s early years, career highlights and tumultuous personal life. Rowling calls Celestina “one of my favourite ‘off-stage’ characters in the whole series”. Rowling also reveals that she “stole” Celestina’s first name from a colleague at Amnesty International’s Headquarters in London where she once worked. The story has been posted today because August 18 is Celestina’s birthday, a fact which is revealed for the first time in this new writing. Both the audio track and the new writing can be found in the ‘Floo Powder’ Moment in Chapter 4 of Harry Potter and the Chamber of Secrets on pottermore.com (new users will need to register).
Celestina is referenced in three of the Harry Potter books. The first mention is in Harry Potter and the Chamber of Secrets (Book 2) when Harry hears her name on the Wizarding Wireless Network (wizard radio) while visiting the Weasley home. She’s eferenced again in Harry Potter and the Half-Blood Prince (Book 6) when she appears on a wizarding radio Christmas broadcast and once more in Harry Potter and the Deathly Hallows (Book 7). In the charity companion book by J.K. Rowling, “Quidditch Through the Ages”, Celestina is credited with recording Puddlemere United’s team anthem “Beat Back Those Bludgers, Boys, and Chuck That Quaffle Here” – another of the four songs featured in the singing sorceress’s live show at Universal Orlando Resort.
