Moving footage of Sol3 Mio's Pene Pati breaking down on stage has been viewed by nearly 10,000 people across the globe.
The opera singer's uncle-in-law was one of the people shot in Christchurch's horrific mosque massacres.
"My wife cries from the other side of the world today as her uncle is one of the injured, still waiting on hospital [to hear] whether he has survived or not, in the incident today in Christchurch," Pati wrote on Facebook on Friday.
Pati is married to successful soprano Amina Edris who is an Egyptian-born New Zealander.
It is not clear what the uncle-in-law's condition is.
Singing their own remix to Coldplay's Fix You, Pati was captured, standing next to his brothers Moses Mackay and Amitai Pati, shedding tears for his loved one.
The song was an emotional tribute to Pati's beloved uncle-in-law and all the other victims involved in the horrific shooting.
He said his heart broke and he felt powerless.
"I refuse to believe the news. Tonight, I will sing for my people in Christchurch.
"This is not us. We are not violent people. This has NO place in Aotearoa. In my solitude on stage, I will have you in my thoughts and may my voice console you. I am truly heartbroken. Come together, NZ," he wrote.
In a later post, Pati tells viewers, with anguish in his voice, "this is not New Zealand and violence has no place here."
"I'm emotional about it because my wife is affected by it. Her uncle is one of the people who have been shot. Why is this happening New Zealand?"