The show must go on even if two artists - Miley Cyrus and Celine Dion - could not hold back tears during their performances at the Billboard Music Awards.

Fans flooded social media with their praise of how Cyrus, 24, is no longer aiming a wrecking ball at anything and everything, including her own personal life.

Instead, in performing her new single Malibu on Sunday, she displayed a new-found maturity and simplicity, noted E News.

Decked out in a cowboy hat, white off-the-shoulder top and white cut-off shorts, she marked her return to her country roots with a pared-down performance of the low-key song.

She broke down towards the end of her performance of the song, inspired by her renewed romance with 27-year-old actor Liam Hemsworth.

Dion, 49, also struggled to hold back her tears when she performed her huge 1997 hit, My Heart Will Go On (from the Titanic movie), reported The Sun.

Her husband Rene Angelil, who managed her career, died last year from throat cancer.

They were married for 21 years.

Dion had told the press after his death: "Before he left, it was very, very difficult for all of us.

"So when he stopped suffering, I said to myself, he's okay. And he deserves not to suffer."