Miley Cyrus was too overcome with emotion to sing at Janice Freeman's memorial service.

Miley Cyrus

Miley Cyrus

The 'Nothing Breaks Like a Heart' hitmaker - who mentored the aspiring singer on season 13 of 'The Voice' - paid tribute to her friend, who died from complications of lupus and a bronchial infection earlier this month, and pledged to always be her "sister" at the memorial on Monday (18.03.19).

She tearfully said: "Before we sing this song for Janice, I just want to clear up a rumor. I was never her coach, ever, she was always mine.

"I learned more from her than anyone that I've ever gotten the honour to be in the room with, not just vocally, I should've gotten more lessons than I did, but she taught me everything that I know about love.

"I had planned on singing a song for her, but just losing her is just too much for me. So my dad's going to take care of this for me. But, I'll always be your sister, and I'm here for you, and I'm here for your family, and Janice I'll miss you more than I could ever say. So, my dad is going to do this for me."

The 26-year-old singer's father, Billy Ray Cyrus then began to sing 'Amazing Grace', and Miley eventually joined in with the lyrics.

She said afterwards: "Thank you for letting us be a part of your family and thank you Janice for letting me be your friend -- it's been an honour."

Billy Ray added: "Thank you sister Janice - I learned from you, too."

Shortly after Janice's death at the age of 33, the 'Malibu' hitmaker paid an emotional tribute to her friend on Instagram.

She wrote: "I miss you so much it hurts. Everywhere ... but so did you. So often. So much pain and no one would ever notice because of the smile and joy you constantly radiated. I am trying my best today to celebrate your existence but I can't help but just deeply mourn over your absence.

"All those texts I would receive, just of you telling me that you're praying for ME.

"How you were so selfless I'll never understand. The way you found the good in everything. You are now a rainbow. Something beautiful that comes after something so gloomy."