As Mukdad played scores he had composed in secret while living under the militants' austere rule, explosions and gunfire could be heard from Mosul's western districts where U.S.-backed forces are still battling Islamic State for control.
"This is a place for all, not just one sect. Daesh represents no religion but is an ideology that suppresses freedom," Mukdad told Reuters, using a derogatory name for the militants. "Everything about Daesh is wrong."
Mukdad, 28, fled Mosul after Islamic State fighters stormed his house and confiscated his instruments, deeming his music a violation of their hardline interpretation of Sunni Islam.
Wednesday's hour-long concert marked his first return to the city that was overrun by Islamic State in 2014.
Mukdad said he chose the Tomb of Jonas, or Mosque of the Prophet Younis, as the site is known by Muslims, to symbolize unity.
"I want to take the opportunity to send a message to the world and send a strike against terrorism and all ideologies which restrict freedom that music is a beautiful thing," he said.
"Everyone who opposes music is ugly."