"My son Liam was diagnosed with cancer - Leukemia - four years ago," Dan Smith, aka Pressure from Aussie hip-hop group Hilltop Hoods, tells me. "His chemotherapy took place over a six month period where he was confined to a room. Through the Dark came from my words to him to keep him positive, and keep him strong, and give him a bit of courage."
Now Hilltop Hoods has teamed up with Google Play Music to create an incredibly powerful and unique interactive film for the song. Sharing a father and son's journey through two 3D animated worlds, Through the Dark is also helping to raise money for young people living with cancer.
Through the Dark almost didn't make it on to Walking Under Stars, the Hilltop Hoods' 2014 album.
"Initially when I wrote the song it was just for Liam, a personal thing I'd written for my son," Smith says. "Suffa [aka Matt Lambert], my offsider, convinced me to put it on the record".
The feedback was "overwhelming", Smith says. "People writing in sharing their stories with us, their similar experiences, and we realised after some time that it was quite special what had been created. It has touched and connected with so many people".
Sophie Hirst from Google Play Music says that when approaching the band, she wanted to really wanted to co-create something with them, "and we sort of went blue sky, like, what would you guys want to build? What's important to you?"
"We came to Google with some pretty big demands", laughs Smith, "'We want you to build an interactive 3D film clip and start a charity!'"
For every person who listens to Hilltop Hoods' latest album on Google Play Music via the link at the end of the film, Google and Hilltop Hoods will donate $1 to youth cancer organisation CanTeen, on their behalf.
CanTeen's CEO Peter Orchard said that the money raised will help fund the development of a new project called Side of Stage, which will give young people affected by cancer special access to live music shows across Australia.
"Every year, another 23,000 young people have their world turned upside down by cancer. They often feel incredibly isolated and many miss out on fun experiences like seeing live music that should be part of a carefree adolescence," Orchard said.
"Music is also widely used as a therapeutic tool for adolescents and young adults affected by cancer as it can help to improve anxiety, mood, and pain."
As you watch the Through the Dark, you can tilt and rotate your phone to navigate through the "dark" (fear) and "light" hope) worlds. It also works on desktop, controlling it with your trackpad or mouse.
Behind the scenes, this film is made entirely of code. Using 3D cameras mapped to the phone's accelerometer, the film uses mobile technology combined with 3D modelling and animation to capture the sense of a world turned upside down.
You can watch Through the Dark here on any desktop and hi-spec Android phones (they need to be newer models since the film is in-browser and uses a fair bit of RAM).
And make sure you have some tissues handy - this is a moving piece of music - and don't say I didn't warn you.
"Cancer is something that affects us all at some point in our lives, whether a personal struggle or someone close to us," Smith said. "Through a collaboration of music and technology we seek to empower and give strength to the suffering, and our listeners can do the same by donating generously."
If you're a musician and want join CanTeen's Side of Stage initiative, you can register your interest here.