For several weeks, the team that runs Bend’s Les Schwab Amphitheater has been touting improvements to the venue that they hope will bring bigger touring acts to town in the future: An expanded stage to accommodate larger productions. Private box seating available — for a sum — to businesses and VIPs. Accessibility enhancements to ensure all who want to are able to attend a show at the Schwab.

But the first new thing concertgoers encountered as they approached the venue Sunday night was an additional layer of blue-shirted amphitheater employees enforcing the venue’s new health and safety protocols, installed to protect attendees, artists and crew against COVID-19. Starting last weekend and running through the rest of the 2021 season, Les Schwab will require proof of full vaccination or a negative COVID test collected within 72 hours of the show to enter. (For the Dave Matthews Band on Sept. 8 and My Morning Jacket on Oct. 3, the negative test will need to have been collected within 48 hours of the show.)

Sunday proved to be a good time to roll out the new protocols. The headliner was Modest Mouse, a Northwest-based rock band that’s popular but not mega-popular; in multiple visits to Bend over the past 15 years, they’ve never sold out a show at the Schwab. This year, the band played two concerts in Portland on Friday and Saturday nights, which no doubt kept most of their fans on the western side of the Cascades from traveling to the Bend show.

As a result, only about 4,100 people showed up Sunday night — just over half the amphitheater’s 8,000-person capacity. This made for short lines to enter and a security process that — 30 minutes before showtime, at least — was quick and easy, even with the added step. It went like this: Show your card (or test result) to the first person and receive a stamp on your hand, then let the next person review the contents of your bag and/or your pockets. Next up was a brief stop at the hand-held metal detector, followed by the taking of concert tickets. All told, it took a minute or two, and my experience was probably a little longer than typical because my friend wore a fanny pack that received extra attention from security, and not because it was a handsome and contemporary fashion statement.

Inside, one is immediately confronted by the new amphitheater experience. Where once the gates gave way to open grass and a clear path to the stage, there now is a front-and-center place to buy drinks, specifically “Craft Beer” and “Vodka Lemonade,” according to the signage. Off to the right, toward the Deschutes River, are eight “cabanas” perched atop the amphitheater’s tallest hill, perfect for corporate hobnobbing and half-paying attention to the show. Off to the left, toward Shevlin-Hixon Drive, is the Deschutes Deck, a towering two-story collection of stadium-style seating that was mostly empty Sunday night. At what looked to be about 30 feet tall, it was the most striking of the Schwab’s new features.

What’s that? Oh right … there was a concert, too. After a solid opening set of mildly new wave-ish indie rock by Philadelphia band The Districts, the seven members of Modest Mouse spilled onto the stage at exactly 7 p.m. and launched into “Night on the Sun,” a 20-year-old song that never appeared on an album and a strange choice for an opener, especially as compared to what came next: “F**k Your Acid Trip,” the first track on the band’s new album, “The Golden Casket.” It was as if some record label marketing guy wrote the setlist, and then main Mouse Isaac Brock came along and stuck a curveball onto its front end just to mess with people. Which would be very much in character for the famously prickly frontman.

The last time Modest Mouse played the Schwab, in 2017, the show started very late, and then Brock spent much of the night joking about how the show started very late. (It wasn’t funny.) But he was on his best behavior Sunday night, leading the group through two hours of songs from across its catalog, including at least one from each of their seven official albums. The first half of the set had its ups and downs: The woozy vibes of “Leave a Light On” translated nicely to the live setting, but Brock came nowhere close to hitting the high notes in the chorus of “Missed the Boat,” one of the band’s catchiest songs. Just as the sun sank behind the mountains, though, the gruff, rubbery groove of “Tiny Cities Made of Ashes” gave Brock and his mates a chance to rock out and brought their light show to life.

After a handful of clunky songs I’m choosing to blame (mostly) on Brock’s banjo, Modest Mouse finished strong … until it didn’t. They closed the main set by serving up lots of distinctively warped guitar sounds as part of “Satellite Skin,” then took a five-minute break before a generous seven-song encore highlighted by oldie-but-goodie “Dramamine,” the strong new single “We Are Between” and a raucous version of “Doin’ the Cockroach,” complete with a perfectly timed train-teetering-off-the-tracks ending. If I were in charge of the show, it would’ve ended right there.

Instead, the band played a spirited version of one of its more brutish tunes, “Bury Me With It,” then ended feebly with “Out of Gas,” an excellent old song that never gained an ounce of momentum and ended abruptly. For a minute or two, conditions on the stage — lights down, house music off, equipment untouched by roadies, etc. — seemed to tease another encore, presumably to play Modest Mouse’s biggest hit by far, “Float On.” But the band never came back out, and eventually the lights came up, the music started and the night was over.

It was a bizarre way to cap a seesaw of a show, but perhaps that’s appropriate since Modest Mouse is one of the weirder bands to achieve mainstream popularity over the past couple of decades. And given that I hadn’t seen any live music since Hot Snakes played Volcanic Theatre Pub nearly 18 months ago, I walked out of the amphitheater feeling just happy to have been there.