This year marks the 30th anniversary of Red Butte Garden inviting guests in—and its 28th year of hosting concerts. The venue has come a long way since the days of Sunday lawn shows, when tickets were $10 and jazz trios and local bands headlined.

Red Butte's annual summer concert series has grown from four concerts a year to 28, with bigger and bigger names appearing each year. Chris Mautz—co-owner of both The State Room in Salt Lake City and O. P. Rockwell in Park City—handles booking bands for the venue, and is partially responsible for this trend; it also helps that, in 2008, the amphitheater underwent a $6 million renovation.

In determining the lineup for the series, Mautz says, "There's not any set formula or checklist that we cross off. It's about feel and each individual artist, how it would be a blend and a contributing force in the overall lineup."

"We're still trying to go back to the roots of the thing, which is a very eclectic and diverse lineup, and trying to offer a little bit of something for as many people as possible," says Mautz.

Since Mautz books bands for his own venues and the Garden (as well as another garden venue in Michigan, the Frederik Meijer Gardens), he gets to see bands start as openers at Red Butte, to headlining at one of his venues, and then graduating into headlining back at Red Butte. For example, Alabama Shakes played (and sold out) The State Room in 2012—before they had even released their debut album—and this summer, are headlining a Red Butte show on August 4.

"That's kind of neat. It's nice to see artists grow, and be able to participate in that," says Mautz.

Now that Red Butte has ramped up to (and found its groove in) a 28-show summer series, Red Butte's communications director Bryn Ramjoue and Mautz say it will continue with more of the same approach in the future: The same number of shows, and the same attempt to appeal to both younger and older crowds. There isn't going to be anything specifically anniversary-related during the 2015 series (and although not intentionally celebratory, 28 shows for 28 years of concerts is certainly appropriate). According to Ramjoue, "We just did what we do best."

Passion Pit, Holychild
The kick-off concert in Red Butte this year is headlined by Passion Pit, a glittery indie-electronica synthpop band from Massachusetts. Passion Pit have played Salt Lake City before (at The Complex and In the Venue), but this is their first time playing an outdoor concert here, and the band has new summery material, from their April release, Kindred. The album is as falsetto-heavy as past albums, but more tracks sound like they have an '80s-influenced production. Their opener, Los Angeles-based Holychild, is a Red Butte veteran, having opened for Fitz and the Tantrums there last summer. This year, the brat-pop duo is releasing their first full-length album, The Shape of Brat Pop to Come. Their sound is like rock candy—sugary, but with plenty of edge. While the pop music is as sweet as cherry ChapStick, the lyrics are heavier and deeper, about power and gender dynamics, money and class disparities. May 22, 7:30 p.m., $25-$40

The Decemberists
The Decemberists are riding the wave from the Sasquatch! Music Festival in Washington and Big Sky Brewing Company in Missoula into Red Butte Garden. The Portland, Ore., indie folk band is back from hiatus with their newest release, What a Terrible World, What a Beautiful World. The album came together in a much different way than the band was previously used to working: Instead of spending four or five weeks in the studio to record, they went in for a few days at a time over a two-year period. The tracks on this album are more personal, and influenced by Colin Meloy's new project of writing children's books. The name of the album comes from the track "12-17-12," which was named for and inspired by the date President Obama addressed the nation after the Newtown school shootings. This tour is far different from the last time the band played the Twilight Concert Series in 2011 and Kilby Court in Salt Lake City in 2004, but the concert promises to be no less engaging. Meloy is a theatrical performer who encourages the audience to participate—like when Meloy pulls fans up onto the stage to fill in the anarchy in "Chimbley Sweep." Missoula orchestral folk band Wartime Blues opens. May 26, 7:30 p.m., $35-$50

Chromeo, Odesza
Chromeo, a Canadian R&B electro-dance outfit with an '80s-funk vibe, are headlining the outdoor dance party with a set list from their booty-shaking 2014 release White Women, as well as tracks from some of their earlier records. Live shows are as relentlessly energetic as their studio albums, and even more theatrical. Pee Thug's synthesizer sits on a pair of plastic woman's legs, and Dave 1 has been known to bust into scorching, metal-tribute guitar solos. They are joined by Odesza, an experimental, electronic dance group from Seattle, who are touring their smooth, tribal-sounding album In Return. The captivating visual effects are like a gigantic psychedelic kaleidoscope, adding to the trance fever that is their performance. May 27, 7 p.m., $30-$45