Grant Park Fest’s all-summer concert party begins with a selfie of bad-news Belshazzar

Review: Summer’s obviously just over the horizon: The musicians, chorus, maestro and devotees of the Grant Park Music Festival are already partying like the equinox has happened. As the centerpiece of the festival’s 84th summer opener, June 13-16, William Walton’s grand and colorful oratorio “Belshazzar’s Feast” felt like a reflection of the block-party atmosphere at Millennium Park.