INDIO, California, April 12 (Reuters) – Brazilian DJ Alok delivered an energetic fusion of electronic dance rhythms during his Saturday performance at the Coachella Valley Music and Arts Festival, even as global artists grow increasingly concerned about the challenges of performing in the United States. "As a Brazilian, securing a visa has always been tough," Alok shared in a backstage interview with Reuters at the Southern California event. "So, honestly, not much has changed