"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.