Three weeks ago, Rod Stewart canceled the remaining dates on his farewell tour after undergoing “a routine coronary stent procedure.” Those dates included a Tuesday night stop at the Minnesota State Fair Grandstand, leaving organizers to scramble for a replacement.

The Fair staff ended up booking a killer lineup of metal and arena rockers, including KISS, Motley Crue, Poison and Bon Jovi. Sort of, anyway. Minneapolis cover band Hairball replicated hits from those acts, along with many others, Tuesday night in what became a free show — with tons of pyro.

It was a savvy decision. Retro metal acts tend to do well at the Grandstand and, well, Hairball has lead singers who can still sing. And it’s actually the band’s second appearance on the big stage. They made their Grandstand debut in 2018 and drew a crowd of about 7,500, and that was with $15 tickets (a bargain, yes, but not as much of a bargain as free).

While not necessarily big stars in the Twin Cities, Hairball has a strong following in Greater Minnesota and surrounding states thanks to their commitment to touring. Their summer schedule has included shows at casinos, county and state fairs and festivals in Minnesota, Ohio, Kentucky, Wisconsin, North and South Dakota, Nebraska and Iowa.

Minneapolis’ own Slave Raider, who tried valiantly to break through to the masses in the late ’80s, opened the show, which ended up attracting 7,599 fans, some of whom used the free admission as an excuse to grab another beer or two (or four).

What sets Hairball apart from the pack is their commitment to the bit. The band’s two lead singers not only attempt to recreate the vocals of the stars, they also dress the part, even if some of the wigs are questionable.

They opened with a run of four KISS songs — “I Was Made for Lovin’ You,” “Shout it Out Loud,” “I Love it Loud” and “Rock and Roll All Nite” — in full Paul Stanley and Gene Simmons drag. The latter even did the breathing fire bit.

From there, some of the bands were represented by two numbers: Poison (“Nothin’ But a Good Time,” “Talk Dirty to Me”), Def Leppard (“Photograph,” “Pour Some Sugar on Me”), Motley Crue (“Kickstart My Heart,” “Girls, Girls, Girls”) and AC/DC (“TNT,” “Thunderstruck”).

Others just got a single song, including Bon Jovi (“Livin’ on a Prayer”), Twisted Sister (“We’re Not Gonna Take It”) and Quiet Riot (“Cum On Feel the Noize”).

Given all of the costume changes, it was impressive to see how seamless they kept the transitions. And hearing hit after hit after hit turned out to be more exhilarating that exhausting.

The best song of the night was also the most unexpected, a spirited run through Rush’s “Tom Sawyer.”

Not all of the vocals worked, like the limp Prince impression on “Let’s Go Crazy.” Then again, anyone attempting to pull off a Freddie Mercury on “Bohemian Rhapsody” deserves credit for trying, even if it wasn’t anywhere near a slam dunk. Hairball was big, dumb and noisy enough to make up for it.