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The last day of a major festival produces mixed feelings: dread that normal life will resume at the end of the night, and relief that at the end of the night we can get out of the sun and into a REM sleep. Sunday, 90,000 more-or-less tired souls headed out into the heat of the day and even hotter music for the last time at Firefly 2016.

City of the Sun, two guitarists and a percussionist at the tiny Treehouse Stage, contributed driving rhythms and excellent vocals to start the day off right. The Struts put on their glam-rock show on the big lawn stage, vamping and posing throughout their memorable songs. Front man Luke Spiller engages a crowd the way a frontman should, and “Put Your Money On Me” became an anthem for the afternoon. The group then stripped off the gauze and sparkles and moved to that same little Treehouse Stage, where sweat may have smudged what little mascara remained but not dampened the music one bit; most of the crowd had just seen them, and was ready for more, shouting along with “Could Have Been Me,” as Spiller spilled out onto a walkway among them, both riling up the audience and taking from them: catching sight of a David Bowie placard, he unleashed an impromptu Bowie homage. That the crowd followed the Struts from one stage to another to hear them twice in one day—by definition ignoring six other stages—speaks volumes about this band’s drawing power.

Long-running favorites Earth, Wind & Fire  gave the youngsters a taste of showmanship in addition to very special music.  The crowded stage bristled with dance, song and instrumental talent as the band powered through the R&B, soul, funk, jazz, disco, pop, rock, Latin and African hits which have not only changed our perceptions of popular music but have kept us dancing since 1971—only a couple of years after festivals like this came to be.

I expected another pop Diva in Elle King, and instead was treated to a honky-tonk angel. Flipping her hair, spangles and fringe skirt, King also flipped the bird and trashed-talked with the best (and worst) of them. Who would have thought the same gal who gave us “Ex’s and Oh’s” would be capable of a very Cash-worthy version of “Folsom Prison Blues”? Not me, but King carried that song and the rest of her show with the panache of the country/blues/soul singer she’s been hiding from mainstream radio.

Bluegrass purists have a bone to pick with Mumford & Sons, the British invaders of that very blue-blooded Americana genre. Electricity, drums, a towering backline…it’s said they have no place in bluegrass, but Mumford & Sons puts all those elements to good use along with their standup bass, mandos, banjos and catchy tunes whose bluegrass origins clearly have been blown up to major proportions, suitable for stadiums and crowds like Firefly. Honestly, I love it. Blasting, shouting, posing on risers and silhouetted by a sophisticated light show, Bill Monroe wouldn’t fit in with this band, but that doesn’t make Mumford & Sons’ music second-rate: this is first-class music. Traditional bluegrass and Mumford-grass share two unmistakable elements: the energy and pace. Lightening-fast and just as jolting, these four guys and a couple of sidemen shot through almost two hours of music at breathtaking speed with precision and power. Tradition is great, but I’m not sorry the blues birthed rock, or that Sam Bush birthed Newgrass. Mumford & Sons can take a leap, too, and build a backline to the heavens, for all I care. It’s all good music.

—Suzanne Cadgène