Not even 40 minutes into the Beach Boys’ performance Monday at the Minnesota State Fair’s sold-out grandstand, frontman Mike Love announced, “We’d like to take an intermission. Followed by a nap. That’s what you get for coming to see a couple of used groups.”

He was referring to the Beach Boys and the Righteous Brothers, two Rock Hall of Famers who made their names in the 1960s and shared the stage on Monday. Fifty-some years later, these two groups hardly seemed like a vintage Deuce Coupe and a classic 409. No, it was more like a couple of reconditioned Mustangs.

New parts, er, players greatly enhanced both of these classic names in American popular music. For the Beach Boys, former TV star John Stamos has become the resident sex symbol since he’s a generation younger than Love, now 77.

When he was on guitar, Stamos roamed around the stage like he was having a good time. When he was behind the drum kit, he earned his keep. When he stood at the microphone, he talked about “decency being at an all-time low” in our country. “Thank God we have the Beach Boys’ music to get us through.”

Indeed. Too bad he then sang an obscure Beach Boys tune, “Forever,” and Love indulged in a few songs from his 2017 solo album, including the forgettable “All the Love in Paris” and “Unleashed Love.”

Those unfamiliar numbers really slowed the middle of the 1¾-hour set. So did Love’s faux pas before and during the Beach boys’ classic “Be True To Your School.” He introduced the song by saying his nephew, after one year at UCLA, moved to Minneapolis to play basketball. Just then a screen behind the stage showed Kevin Love in a Cleveland Cavaliers, not Timberwolves, uniform. Ouch.

To add further insult, the band’s flutist played an “On Wisconsin” interlude in mid-song and the video screen showed a University of Iowa cheerleader before finally landing on a photo of a University of Minnesota cheerleader and then Goldy Gopher.

Thankfully, Love and his nine-man team recovered after those fumbles. You can’t mess up “Sloop John B,” “Wouldn’t It Be Nice” and “California Girls” even if Love’s thin voice has grown more nasally over the years. And, the crowd of 13,168 loved the 1-2-3 punch of “Help Me Rhonda,” “Barbara Ann” and “Good Vibrations.”

Making their 10th appearance at the fair but first since 1994, the Beach Boys acknowledged their two deceased original members, drummer Dennis Wilson and his guitarist brother Carl.

However, Love didn’t show much love for his cousin, Brian Wilson, the Beach Boys guiding light from whom he’s estranged.

In their opening set, surviving Righteous Brother Bill Medley must have mentioned his late partner Bobby Hatfield 20 times. Medley, 77, filled his hourlong Vegas-y set with lots of talking, pat jokes and praise for his new partner of three years, Bucky Heard. Too bad Medley’s baritone voice wasn’t as smooth as his showmanship, even though he did a touching version of “Unchained Melody,” Hatfield’s old showcase, and a spirited blues tune “This Will Be the Last Time.” And maybe it will be — but the music will live on.