Three teenage mariachi musicians who were temporarily detained by Immigration and Customs Enforcement (ICE) in February have been tapped to open for country singer Kacey Musgraves at several upcoming shows in Texas. On Monday, Musgraves announced that the Gámez-Cuéllar brothers Antonio, 18; Caleb, 14; and Joshua, 12, would join her for performances at Gruene Hall from 3 to 5 May as part of her Middle of Nowhere tour. The last of those dates is Cinco de Mayo, which commemorates a Mexican military victory over a French army at the 1862 battle of Puebla. That holiday is also popular in the US, where communities nationwide celebrate it. Musgraves, a 37-year-old Texas native and Grammy winner, made Monday’s announcement after the Gámez-Cuéllar brothers were arrested alongside their parents by ICE in February – and subsequently released amid a bipartisan backlash to their detention. The two younger boys and their parents were held at a family detention center in Dilley, Texas.…