Happy birthday, Demi Lovato [1]! The singer — who turned 27 on Aug. 20 — kicked off the festivities a day early at pal Ariana Grande [2]'s concert in London on Monday, and Ariana made sure it was a special celebration. In addition to having a candle-lit cake backstage for Demi to blow out and make a wish, Ariana led a birthday chant with her dancers and manager Scooter Braun [3] before the show. "This was too sweet not to post . . . before show prayer they did this for my bday," Demi wrote alongside the sweet Instagram video. "I'm so so proud of you @arianagrande. You f*cking killed that!!! I love you tons."

Demi's 27th birthday comes a year after her nearly fatal drug overdose [4], and we're so happy to see her happy and healthy again. According to People, "Demi is in a great place [5] in her life. She is spending her birthday in London and working on new music and other projects." Ooh, who's ready for some new music?