For all its thrashing guitars and screamed lyrics, the world of heavy metal is actually relatively peaceable. Unlike other parts of the music industry, it wears its politics lightly, with fans much more interested in headbanging to their favourite songs than anything else. While this year’s Glastonbury crowds were a sea of Palestine flags, hard rock fans tend not to bother with such overt virtue-signalling.

So it came as a surprise that, amid the joyous scenes at Ozzy Osbourne’s final gig at Birmingham’s Villa Park on July 5, a performer was apparently booed for being supportive of Israel.