"Shortly after this, Fleur decided to imitate Celestina singing 'A Cauldron Full of Hot, Strong Love,' which was taken by everyone, once they had glimpsed Mrs. Weasley's expression, to be the cue to go to bed"
-- during Christmas Eve at the Burrow (HBP16)
Originally from Wales, Celestina's hits include A Cauldron Full Of Hot, Strong Love and You Charmed the Heart Right Out of Me (HBP16, Pm), and she also recorded a version of the Puddlemere United team anthem Beat Back Those Bludgers, Boys, and Chuck That Quaffle Here as a special fundraiser for St. Mungo's (QA7, Pm).
Concerts she has played include Liverpool (DP2) and Exmoor (JKR), and she is known to perform with a group of backup banshees (DP4). Miss Warbeck also sings Christmas Concerts on the WWN, which the Weasley family listens to enthusiastically (more or less) (HBP16). She is extremely popular with wizards and witches of the older generation and her concerts are sell-outs, with tickets going for high prices on the black market. This is why Molly Weasley has never been to hear her favourite singer live.
She was disappointed by the Ministry's plans to curtail the celebration of Hallowe'en, as she had planned a large open air concert to promote her new album You Went and Stole my Cauldron but You Can't have My Heart (DP4), which was nevertheless a massive global hit for her (Pm).
Celestina has always had an extraordinary voice and her mother was initially reluctant for her to go to Hogwarts - where Celestina was sorted into Gryffindor. Her mother continued to press the school for choir, theatre and dancing facilities to further develop her daughter’s talent (Pm).
Ability to drown out a chorus of banshees, singing, tap-dancing (Pm)
Other canon notes and references
A celesta is a musical keyboard instrument with keys that are played to make hammers strike metal plates, making a soft tinkling sound (the tinkling, magic-sounding instrument which plays "Hedwig's Theme" in the film soundtracks) (Oxford English Dictionary). The name also derives from the French names Celeste/Celestine and the word celestial, all of which mean "heavenly" (Behind the Name).
To warble is English for "singing in a trilling or quavering voice (as in a bird song)" (Oxford English Dictionary). The only historical Warbeck is Perkin Warbeck (c.1474-1499), who was a pretender to the English throne (Wikipedia).
Rowling wrote that she always imagined Warbeck looking like singer Shirley Bassey:
From the Web
Writing by J K Rowling on Pottermore: Celestina Warbeck