Cardi B carried on for only 50 minutes last summer at Target Center. The over-the-top hip-hop hitmaker might have spent more time doing her hair and makeup.

ZZ Top exited the Minnesota State Fair grandstand after just 63 minutes. Does their Rock Hall of Fame career still have legs after 50 years of touring?

Minneapolis music hero Alexander O'Neal performed for a mere 45 minutes at the Dakota last month. That gave new meaning to his hits "Criticize" and "Fake."

How long should a concert headline set last? That was the question pondered by Twin Cities pop-music lovers who witnessed several shortish efforts in recent months.

The answer is not an easy one. It depends on the experience, age and reputation of the artist, the number of opening acts and the ticket price.

Ultimately, though, it boils down to expectations.

Getting their money's worth

Ask performers, promoters and fans, and the consensus is that 75 to 90 minutes is expected from an established headliner.

"You do want to give people a full show for their money's worth," said country-pop star Maren Morris. "I was doing headline shows off one record, which is a stretch. It has to at least be 90 minutes if you're headlining in a good-sized venue."

Avid concertgoer Kyle Matteson of Eagan attends more than 125 shows a year in all kinds of venues.

"If I'm paying upward of 100 bucks and a band plays less than 90 minutes, I'm disappointed," he said.

Mary Brabec has seen it from both sides of the music business — currently as programming manager at the Dakota in downtown Minneapolis, where she books shows, and previously as an agent representing the likes of Southern Culture on the Skids and Pokey LaFarge.

"The base minimum is 75 minutes," she said.

Well, it depends. First Avenue general manager Nate Kranz said the musical genre and the act's experience are determining factors.

"We've all been to hardcore punk shows where the bands are on for 20 or 30 minutes," he said, citing a 7th St. Entry concert by Sacramento punk-rap band Death Grips a few years ago. "They're just so intense. That's part of the experience. I don't know how you'd be able to keep it up for more than 25 minutes."

Kranz says the number of albums an act has recorded also colors expectations.

"We've seen artists go from nobody to headliners in a record amount of time," he said. "It doesn't do anybody any good to stand up there for 90 minutes if you only have 45 minutes of material."

Still, some newcomers are resourceful. Twin Cities singer-songwriter J.S. Ondara, a Grammy nominee for best Americana album, has only one full-length project to his name but managed to play for 90 minutes at First Avenue last month.

"He talked a lot between songs, told a lot of stories," superfan Matteson said. "I was shocked how long it was, but it was so engaging."

Likewise, newly minted solo artist Brittany Howard, frontwoman of Alabama Shakes, added a couple of covers to the material from her debut disc to extend her performance to a crowd-thrilling 75 minutes in September at the sold-out Palace Theatre.

On the other hand, rock hero Jack White's band the Raconteurs has three albums under its belt, but left the Armory stage after a mere 50 minutes in July. They played a half-hour encore, however, leaving the customers satisfied.

Stars have 'sweet spots'

Contracts typically spell out the minimum length of a headline performance — "60 minutes plus," for example — as well as penalties for running into overtime when there are curfews outdoors or in union venues.

Established artists know their comfort zone, but it can vary from night to night. In November, Elvis Costello, fighting a cold, delivered 21 selections in 105 minutes at the State Theatre. A year earlier he offered 30 numbers in 150 minutes at Northrop.

For country superstar Miranda Lambert, who has been headlining tours for 10 years, 85 to 100 minutes is "my sweet spot," she said. "More than two hours will probably wear people out. You should give people enough show for the money they've paid to see, but not too long so they're exhausted. Leave them wanting more."

Unless you're Paul McCartney, Bruce Springsteen or Eric Church. They're known for presenting 30-some songs over more than two hours.

"I've been to Bruce Springsteen shows," Morris said, "and his four-hour marathons just fly by."

ZZ Top certainly left fans frustrated at the State Fair on Labor Day, hardly befitting a band that has recorded 15 studio albums and is celebrating its golden anniversary.

"They were intending to play longer," but cut it short because of an approaching rainstorm, said Renee Alexander, State Fair deputy general manager for entertainment and marketing.

Why not make an announcement then? Fairgoers, who had enjoyed an hourlong opening set by fellow Rock Hall of Famers Cheap Trick, might have been more understanding if they'd known about the circumstances.

Refunds if requested

Expectations can be different at nightclubs. When an act is playing two shows in one night at the Dakota in Minneapolis, ticketholders don't anticipate much more than 60 to 75 minutes of music.

Dakota proprietor Lowell Pickett said he doesn't fret about length "as long as the quality of the show leaves people satisfied, and excited that they saw something special."

If concertgoers complain, whether about length, sound or whatever, promoters will listen.

"Goodwill is better than the harm on social media from one bad experience," said Hennepin Theatre Trust's Lisa Krohn, who books shows at the Orpheum, State and Pantages theaters.

When a performance fails to meet clubgoers' expectations, the Dakota sometimes offers refunds or complimentary tickets to subsequent gigs. "Our relationship with our guests is of primary importance," Pickett said.

He called the O'Neal show "an outlier. I wouldn't have been upset with him doing 45 minutes if the [opening act] was long enough and everything was on time and if his show was really strong." The show failed on all of those counts — O'Neal took the stage two hours after showtime — so refunds were given to those who requested them.

Sometimes fans are simply thrilled to witness one of their heroes in person. So, they don't complain if Cardi B performs for less than an hour in her first headline turn at sold-out Target Center. Or if aging institutions like Tony Bennett and Willie Nelson spend only an hour or so onstage, as they did in Twin Cities concerts last year.

The colorful Cardi was full of unforgettable panache. Tony radiated the joie de vivre of 92 years well lived. And Willie, at 86, was just Willie, with his Zen-like mystique and singalong tunes.

"If you're Willie Nelson," Maren Morris said, "you can do whatever."

Twitter: @JonBream • 612-673-1719