Those who attended the growing memorial outside Dallas Police headquarters Sunday evening were in for a pleasant surprise.

To many in the crowd, it was a man who rode up to the memorial outside 1400 Lamar Street with a grand piano behind his bike, played an instrumental rendition of John Lennon’s “Imagine” and rode off.

To Davide Martello, it was another stop on his global mission “to promote peace.”

As it turns out, Martello, or “Klavierkunst,” travels the world playing his piano. He played in France after terrorist attacks killed 130 people, and in Ukraine during pro-Russian unrest in 2014.

Martello first gained international recognition in 2013, when he played for a large crowd in Istanbul following heavy civilian clashes with police there.

According to his website, he wants to play in every capital of the world with his grand piano.

And the recent tragedy in Dallas -- the death of five officers at the hands of a lone gunman during an otherwise peaceful protest late Thursday -- drew him here to move those in mourning with his piano.

The “colours of his piano keys” -- black and white -- made him come to Dallas on Sunday, he wrote on Twitter earlier Sunday.

“I will play in front of the memorial to promote peace.”

Klavierkunst, in German, means “piano art.” On Sunday, his art was healing in a city that needs it. And he allowed his piano to do the healing.

“He rode up, he played, he rode away. It was all pretty quick and surreal,” said Garrett Haake, a WUSA (Washington, D.C.) reporter assisting WFAA with coverage of the police ambush and its aftermath. Haake captured the brief moment and posted it to Twitter.

On his website, Martello asks for the public’s help in connecting him with authorities in different cities so he can play for people “without getting into trouble.” He asks those who want to help to get in touch with him here.

Enjoy a longer sample of Martello’s music below or here.