Three songs in to Imagine Dragons’ storming show at London’s Roundhouse on June 7, frontman Dan Reynolds takes a moment to dedicate one of his band’s biggest hits, It’s Time, to Manchester.

The May 22 suicide bombing, allied with the Bataclan atrocity in Paris in 2015, has created an intensely challenging environment for the concert industry, and the band were determined to show their solidarity with the city.

“London and Manchester both have been dealt a really heavy card in ...