Every year at SXSW there is a band that reaches mythic levels of hype. Lines wind around blocks with fans and industry well-wishers alike; a status Artic Monkeys and MGMT have enjoyed in the past. This year’s inclusion in the explosive hype department is The xx. The trio had every inch of crowd-space filled at the larger stage at the Other Music party. The bassist/singer Oliver Sim and guitarist/singer Romy Madley Croft traded hazy melodies while meandering through chunky bass and goth-y guitars. The template for their success is simple and deserved. They base everything in a tempo with a slow groove, holding off on percussion as long as they possibly can. And then every so often, bam, syncopated drum machine claps pop in, deceptively making the band feel suddenly electro and dancy. It’s almost like the build-up ensures the payoff. The closing lyric, “I can’t give it up / because I give too much,” repeated endlessly amidst the whirl invoked an encore chant and a near frenzy from the audience.