‘W e’ve done many concerts, but this is the first time I’m stressed,” the first violin confesses with a grin, lowering his instrument before a single note has sounded. But before he can launch into the story he’s interrupted by the cellist. “We’re actually supposed to play first!” she chides. A string quartet is often compared to a four-way marriage. But what if the dynamic was closer to four siblings? One group that doesn’t need to imagine the answer is the Saad family: brothers Omar, Mostafa and Gandhi, and sister Tibah – AKA the Galilee String Quartet . Formed in 2011, the Palestinian ensemble was forced into hiatus in 2013 when eldest brother Omar was summoned for military conscription by Israel’s IDF . Refusing to serve, he was imprisoned as a conscientious objector. The quartet are currently based in Paris, honing their signature blend of east-meets-west music-making. Webern’s lyrical love-letter Langsamer Satz was a strategic opener.…