It’s hard to dislike Trent Reznor: the guy regularly gives away excellent music, goes out of his way to design a visually stunning stage show and even fought through voice problems tonight. While his set got off to a fast start with a hard-hitting combination of “1,000,000” and “Discipline” (both from The Slip) and delivered “Closer” early, Reznor soon settled into some of the complex instrumentals from the Ghosts I-IV album. While the combination of live instrumentation was impressive (when was the last time you saw a rock show with a marimba solo?), the crowd’s interest waned, even with the dynamic lighting display matching the music note for note. It wasn’t until Reznor hit the back half of his set — lead by insane shout-alongs on “Wish,” “Terrible Lie” and “Only” — that the fans really got on board with his particular blend of stadium-sized pathos. During his encore, Reznor mentioned that Nine Inch Nails played the first Lollapalooza 17 years ago, which was a tribute not only to Reznor’s tenacity but also the staying power of the fest.