"Every time I play I think of Yarmouk. I see destruction, children crying and people starving," Ahmad says.
The 28-year-old grew up in the impoverished neighborhood on the outskirts of Damascus that was established as a Palestinian refugee camp three generations ago. He remembers it as a beautiful, vibrant community.
His father -- a blind violinist -- taught him how to play on an old brown Russian piano when he was five, and as a teenager Ahmad knew he wanted to be a pianist. "It is something in my fingers, I just can't stop, it is like a drug," he explains.
He would travel hours back and forth from the Syrian capital to the conservatory in Homs where he studied the works of Mozart, Tchaikovsky and Chopin. Later, he opened his own music shop.
Then the Syrian civil war came, and changed everything: Yarmouk was besieged by the forces of President Bashar al-Assad's regime. Food, water and medicine became scarce, and dodging sniper fire was a daily reality.
But even as a humanitarian disaster unfolded around him, Ahmad was driven by an unstoppable passion for music and a desperate desire to "make the children smile again."
So he pushed his piano into the wrecked streets of his hometown and started to play in the rubble. "I wanted to give the children hope," he says. "They had no food, no school to go to."
The neighborhood's youngest residents would gather around the piano and sing along in a rare moment of relief from the war.
Videos of Ahmad's impromptu concerts spread on Youtube
, and "The Pianist of Yarmouk" became a symbol of courage amid the chaos.
When ISIS took control of the area in April 2015, the situation got worse: The militants banned music, calling it "haram" (forbidden) and threatened Ahmad and his family.
One day an ISIS recruit set the young father's piano on fire; he could do nothing but watch it burn.
"It hurt, but I wasn't sad about the piano, I had plenty more," he says. "I was sad because people were dying in Yarmouk." His voice starts to tremble as he remembers the time a sniper shot a young girl who had come to watch him play. "Her name was Zayda," he says.
Ahmad knew he had to flee Syria, so with the help of a German journalist, he paid a group of smugglers to get him to Turkey, and became one of the hundreds of thousands of refugees making the grueling journey across the Mediterranean and north through Europe.
He made it to Germany in September 2015, at the peak of the country's "open door policy" towards migrants and refugees, and eventually settled in the picturesque city of Wiesbaden, where he was finally able to play again.
A year later, he has become one of the country's most famous pianists
-- and a symbol of hope for those in search of a new, peaceful life in Europe.
He has played nearly 200 concerts, won the Beethoven Prize for Human Rights
, met Germany's chancellor, Angela Merkel and won the heart of a nation inspired by his courage and passion for music.
Now, he lives the life of a musician, traveling from city to city, playing up to three concerts a day and spreading a powerful message. And he has just recorded his first album.
"I am tired, but I can't stop playing. I want to give people hope," he says. "I want tell good stories about Yarmouk, about Muslims and about the Syrian people. We are not terrorists."
In May the young father was granted asylum in Germany; a few weeks later his wife and two sons were able to join him, but starting a new life far away from home has been difficult for the young family.
"My wife is worried, because I travel so much", he says. "But I need to make a living for my family."
He struggles to forget the horrors he has seen.
"I am lucky because my wife and kids are with me now", he says. "But I think about the people that are still there, about my parents and my brother who is imprisoned by the regime. I am worried I will never see them again. It's a lot of pain."
On one of his rare evenings off, Ahmad invites me to his new home to meet his family and neighbors. "We have great Syrian coffee you have to try it," he says with a grin.
It isn't long before his fingers start to twitch, and he sits back down at the piano, his two sons Kinan, 2, and Ahmad, 4, happily by his side.
For a moment all the hardship seems forgotten, and this time he smiles as everyone joins in to sing an old, joyful classic from Aleppo.