Nelly is 43 years old. (Sorry, that was a jarring way to start for those of us that love and grew up with him.)

Nelly is 43 years young. He’s sold more than 22 million records, ranking among the best-selling rap artists in American music history. His first disc, "Country Grammar," released back in 2000, is among the only hip hop albums to be certified diamond. One of the world’s most popular mainstream artists in his prime, Nelly’s made tens of millions of dollars over his career and achieved a sort of timelessness, thanks to his dominance of the mid-2000s. Also, his last album, 2013’s "M.O.," was a total flop.

All of which is the background to understand why, in front of an adoring crowd that spanned the Summerfest age range, dearly wanted to hear his hits and rose to utter ecstasy whenever he played them, Nelly performed on Thursday night like someone who realizes his music has made a lot of people happy and is now old enough to appreciate that fact. Or maybe it’s just the natural personality of a dude who still suggestively pulls up his shirt – to the rapturous delight of his female fans – for "Hot In Herre."

Under a full moon at the new U.S. Cellular Connection Stage, Nelly accomplished the rare feat of seeming an old pro who was still having the time of his life. His set lasted exactly an hour and a half, but throughout it he was dancing, cheesin’, acknowledging his fans – particularly those that have been with him "since day one" – and generally appearing genuinely happy to be there.

Performers often thank the crowd; Nelly thanked someone – the crowd, Summerfest, his family, the band, the Midwest – nine separate times. The gratitude, earned, given his fans’ ardor, felt earnest, almost vulnerably wistful, especially as he continually appealed to those that "have been riding with me since the beginning."

Inarguably, this was a crowd-pleasing set. Nelly led off with a steamrolling, murderer’s row hit parade of "E.I.," "Ride Wit Me," "Shake Ya Tailfeather" (where have you gone, Murphy Lee?), "Batter Up," "Air Force Ones," "Hot Shit" and "Cruise." A rendition of Marvin Gaye’s "Sexual Healing" brought out familiar Nelly – in a white "Derrty" tank top, basketball shorts and sunglasses, still basically ripped and grinning, though without the trademark grill and bandaid.

Accompanied by a seven-piece band – two keyboardists, two on guitars, one on drums, one on sound and "the best DJ in the business" – and two accompanying vocalists, Nelly sounded different. Obviously older, his voice was scratchier, deeper, almost a raspy growl, but still as melodic as the one that’s collaborated on a variety of rap, pop and country songs.

After again thanking Milwaukee and Summerfest and shouting out his family and the "St. Lunatics," he burned through "Get Like Me," "Grillz," "Move That Body," "Millionaire," "All I Do Is Win," "Return of the Mack" and "Get Low." Then, Nelly brought out his cousin for "Tipsy," before announcing to the crowd that he wanted "to do some new stuff right now."

That consisted of a stretch of songs like "All Work No Play," "Freaky With You" – at one point, someone threw a bra; it hit him on the arm and he continued rapping like nothing had happened (Nelly is currently facing a rape accusation) – and "My Place."

Then came the finale, an energetic and charismatic rapper performing some Nelly nostalgia for a craving Summerfest crowd. "If you remember this song in the back, let me hear you," he said before doing "Over and Over." Next was the impossibly perfect "Dilemma," Nelly’s 2002 duet with Kelly Rowland that I may be listening to while writing this review, which generated the strongest crowd singalong. 

Following a last thank-you to Milwaukee, Summerfest, his fans and "the OGs who can’t be here tonight," Nelly did one more song. "Before I go," he began, as the guitar chords played out, and "Just a Dream" started, which felt a little like a commentary, or at least a poignant observation on love lost, or time passed, or just life.

Asking for the crowd’s hands up for someone loved but gone, with the U.S. Cellular Connection Stage swaying and the song sped up so it was more high-energy rap-rock than sad regret track, Nelly closed his set upbeat and grinning, before grabbing a red plastic cup and jogging off, happy to leave his fans happy.