At Wembley Arena in London on Wednesday night, 12,500 excited music fans gathered for what many saw as a landmark moment in British music: the first arena concert to benefit Palestinians in Gaza. Trendy young pop acts including PinkPantheress and Rina Sawayama gave heartfelt speeches or chanted “Free, free, Palestine” onstage. Jamie XX performed a pumping techno set with Sama’ Abdulhadi, a Palestinian D.J. But the audience at the gig, called Together for Palestine, weren’t really there for the music. As the humanitarian crisis in the enclave has worsened and young music fans have rallied to the Palestinian cause, more and more acts have begun speaking out.