The on-stage acoustic of Frank Gehry’s new Jay Pritzker Pavilion in downtown Chicago is a vast improvement over anything the Grant Park Orchestra has known before. Musicians can hear each other, and the overall quality of sound on the stage is something previously thought to be impossible on an outdoor stage. But for the audience, the acoustic “remains a work in progress. Indeed, the quality, depth and presence of sound still varies dramatically from place to place; ironically, the sonics are best at the back of the seating area and on the first half of the lawn.”