Guy Sebastian's smash hit song Choir has been certified platinum (twice!) and earned the former Australian Idol winner two ARIA awards, but there's a devastating real life story behind the upbeat pop anthem.
The song was inspired by his good friend and former band member Luke Liang, who sadly took his own life in 2018.
"I lost a band member and a mate to mental health and he was a really special person and an incredibly talented man," Guy, 38, told Now To Love last year.
The tragedy hit Guy hard.
Just days after receiving the heartbreaking news about his friend, Guy took to Instagram to pen a tribute to Luke.
"My beautiful brother @lukeliang - I woke up today and still can't believe I can't just call you, see you playing to my right at the next gig, listen to you go on about Star Trek, laugh at your hilarious insta stories or just take in the positive warmth of being in your presence," Guy wrote in August 2018.
"I miss you so much dude, I really do. RIP my insanely talented, funny, genuine, humble friend. The stage will never be the same without you."
While Choir initially started off as a heartfelt ballad, Guy decided to change the feel of the song to be more positive and fun.
"Luke made my life better and made life more fun," he said in an interview with Sony Music in 2019.
"I wanted to write something that was more joyful and that made people want to think of his life and celebrate it rather than feel grief, because I know he wouldn't want that."
"So that's where Choir was born, which is poignant but fun and uptempo."
He hopes the song helps fans remember the good memories they spent with those who have passed.
"My hope is that it gives people a different emotion when they're reflecting on their lost loved ones. Choir has a bit of a different emotion to it, it's more a celebration. It's a happy celebration of the good times," he said.
But despite Choir's happy message - its poignant lyrics include the lines "I know you're looking down on us, I'm missing you bro, I hope you're proud of us" - Guy says he still finds the song incredibly difficult to perform.
"The first few times I sang this I was a mess. Even at the Logies, I remember singing it and I got to a certain verse … and just choked up," Guy told 2GB radio.
"I think out of all these tragic circumstances what we've all taken away as a band, even just within our close-knit music community, we are checking up on each other so much more," he said of the song's lasting impact.
WATCH BELOW: Guy and Jules Sebastian recall the first time they met. Story continues after video.
The track has also become an anthem for mental health sufferers and domestic violence victims, who say the song has helped them find the courage to seek help and leave abusive relationships.
"Choir is the song I've probably received the most letters and comments about," Guy told Now To Love.
"Just so many people writing in saying the song has helped them with mental health battles of their own or celebrating someone they have lost," he said.
"It was almost an anthem for some women who said 'It's helped me find the inner strength to leave my partner'. I've had so many stories from women who write in and say 'I was beaten within an inch of my life, but your song helped me through it'."
And that, more than any award or platinum record, is what Guy is most proud of.