By Fiona Sturges @ FT.com, July 1

In 2015 the British journalist Alex Marshall came across a song online. Sung in French, it had a catchy melody and sounded, he thought, like a “Parisian Bieber”, though closer inspection revealed it to be far from a regular pop song: “We need to enter France,” went the lyrics. “It’s time for it to be humiliated. We want to see suffering and death by the thousand.” Eight months after it appeared online, a string of terrorist attacks occurred in Paris, the biggest of which saw 90 music fans murdered during a concert at the Bataclan theatre. In The Music of Isis, the first episode in the American podcast series Pitch, Marshall looks at the use of songs by Islamic militant groups to boost the jihadist cause. Music is usually meant to be joyful and unifying, though the songs by Isis, which usually forbids listening to or making music, are made to divide and destroy [....]