People gathered at a memorial outside the Dallas Police Department were taken by surprise on Sunday when a man pulled up on a bicycle, a piano in tow. Without saying a word, the gentleman began playing a rendition of John Lennon’s “Imagine.”

A witness told CNN the mystery pianist left without saying a word, refusing to speak to reporters as he cycled away. However, Davide Martello, also known as Klavierkunst, did identify himself earlier in the day, tweeting that he would be performing in Dallas.

Martello tweeted Sunday, “the colours of my piano keys inspired me to come to Dallas today.”

Five police officers died and eight were injured when Micah Xavier Johnson opened fire during a demonstration against police violence in Dallas last Thursday.

Previous performances

It’s not the first time Martello brought his music to the scene of a great tragedy. Last year, the German pianist performed “Imagine” in Paris following the terrorist attacks in January and November last year.

CNN’s Hala Gorani was reporting live from outside Paris’ Bataclan theater following November’s attacks, when Martello began to perform.

The pianist, who says on his website that he wants to play “in every capital of the world,” also performed in Istanbul’s Gezi Park during the demonstrations there in 2013, and in Kiev during the Maidan revolution in 2014.