They survived the Holocaust, and held on to their love of life despite their childhood ordeal and in their twilight years, now living in the United States, they started a band.
This week, the two grandfathers returned to their homeland Poland to pay their respects to the victims of the Nazi German genocide and to perform at the site of Warsaw's wartime Jewish ghetto.
Peering at the crowd from behind his drum set on Wednesday night in the capital, 91-year-old Saul Dreier yelled into the mic: "Is everybody happy?" The crowd cheered.
The dynamic duo came to "play for the people that perished and to play for the peace of the world. As simple as that", the retired building contractor said.
Dreier, who welcomed his first great-grandchild last week, survived three concentration camps and lost most of his family in World War II.
"My parents were burned in Treblinka. Either Treblinka, Majdanek or Belzec. I don't know which one," he said, referring to death camps set up by Nazi Germany in occupied Poland.
"And the rest was burnt in Auschwitz", the largest Nazi German death camp where 1.1 million people, mostly European Jews, lost their lives.
While Dreier sometimes joins in, the lead singer in the band is Reuwen "Ruby" Sosnowicz, who also plays accordion and keyboard.
Together, they mainly perform klezmer music, traditional Jewish songs from Eastern Europe.
Sosnowicz, 88, was back in his native Warsaw for the first time since he escaped the ghetto and hid in a barn for three years thanks to a kind Polish farmer.
"Some people were nice people. They helped, you know. The farmer did a big thing. If they would find out that he did it, they would kill him," said Sosnowicz, who is more low-key than his fast-talking bandmate.
'Miracles in our music' :
Non-Jews who stood up to the Nazis have been honoured as "Righteous Among the Nations" by Israel's Yad Vashem Holocaust remembrance centre.
Some of them attended the packed concert, sharing in the joy of the evening as hundreds of music lovers danced, sang along and drank beer.
The band was joined on stage for part of the gig by the youthful and folksy Warsaw Sentimental Orchestra, plus popular 52-year-old Polish rocker Muniek Staszczyk, who said: "It's a great honour to be with the boys."
"Their optimism is contagious. They're full of life," audience member Justyna Tarnacka said of the Holocaust Survivor Band.
"It's phenomenal. I admire these people. They have so much energy. We might not have as much at 90 if we even live that long," the 32-year-old television journalist said.
Dreier attributes their good health and vigour to "God and miracles".
"We had miracles in concentration camps, we had miracles in hiding, now we've got miracles in our music," he said.
He was inspired to start the band two years ago when he read an obituary for 110-year-old Alice Herz-Sommer.
She survived Terezin concentration camp by playing the piano.
"When I saw this, it hit my heart," Dreier said, saying he immediately went to his wife with the Holocaust Survivor Band idea.
"What? You crazy?" was the response. His rabbi later told him, "What you need this for?"
"And because those people tell me no, I said yes!" Dreier exclaimed, adding: "I went out the following day and bought a set of drums. Brand new."
His search for a bandmate led him to Sosnowicz, a hairdresser and lifelong musician, or as Dreier put it: "Not only he's a musician, he's a master musician. He's number one."
'The best healer' :
The idea came at a good time, according to Sosnowicz's daughter Chana Rose, who had moved back in with her parents to help them out.
She later went on to become the band manager and a fellow musician, doing backing vocals and percussion for the Holocaust Survivor Band.
"My mom got very sick, she had a massive stroke. And, you know, dad went into a depression... My first inkling was, 'Wow this would be great for dad,' " she said.
They have since played nursing homes, synagogues and other local Florida venues, even The Venetian casino in Las Vegas. In Poland, they also brought their instruments to Auschwitz and Treblinka.
"Music makes you alive. Even during the war, we played music. We didn't have what to eat but enjoyed music," Sosnowicz said.
"Music is the best healer in life."