The song was an instant hit and stayed at No 1 for six weeks.
Ruma Karaitiana of Palmerston North was the only son of Ruru and owns the rights to his father's song.
"He died when I was 20.
"The last six years of his life he was quite ill."
Ruma said it was never going to be easy for the young Māori Battalion soldiers on their return to their pā.
"They did not want to tell the aunties that they had not brought their cousins home with them."
Those cousins, he said, were buried in war graves on the other side of the world.
Settling back into life after the war and what they had seen was indelibly printed in their minds.
"My father never spoke about the war."
But for a musician like Ruru who discovered opera in Italy, he joined dance bands and started touring on his return home.
"His name was always with the song and he was recognised everywhere he went.
"The song never goes away.
"It is evocative of a period in our history and has a life of its own."
Ruma said he still receives royalties for Blue Smoke with the latest from Europe for a cult movie.
Blue Smoke is on the soundtrack for Angel at my table and Out of the Blue.
The documentary, Pixie: The Voice of Blue Smoke screens Anzac Day, 8am and 3.30pm on Māori Television and online at Māoritelevision.com.
• To make a donation to the RSA visit this Givealittle page
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