As an indie rock band gains popularity and starts to move from performing in clubs to concerts in theaters, it must find that delicate balance between the intimacy and eccentricities that were part of its initial appeal and the broader gestures that draw in a larger audience. Plus, as the band gains new fans, some of its original supporters will view even the slightest nod toward mainstream acceptance as an act of treason.
The Los Angeles band Rilo Kiley is on that cusp — its most recent album, “More Adventurous,” was released by its own Brute/Beaute label, distributed by Warner Bros., and their performance Sunday night was the final show of a first theater tour. That show demonstrates the band is more than ready to make the leap to the next level.
The tour has certainly given the members of Rilo Kiley confidence — opening number “It’s a Hit” announces itself with a heraldic fanfare of horns (and the lyrics include a pointed comment on indie rock fecklessness: “It’s a sin when success complains”). Band members have gained the chops to back it up; the band is tighter, the arrangements more focused, and the entire sound is meatier.
Most importantly, while it has bulked up, Rilo Kiley retains its melodic charm. The guitars on “Hail to Whatever You Found in the Sunlight” have the spacey sweep of Love. As the narrator of “Does He Love You,” about a love triangle, sees her fantasy receding further and further into the distance, the music becomes more aggressive, moving from the picket fence innocence of the opening synth line (with its echoes of “Til There Was You” from “The Music Man”) to louder and more distorted guitars, ending in a wail of feedback and a coda of harsh strumming.
They also keep their sense of fun, bringing Deborah Gibson onstage to sing her hit “Lost in Your Eyes” or ending the evening by bringing their opening acts Feist (whose solo set found her earthier than her intriguing Interscope debut “Let It Die” would lead you to believe) and the Brunettes (a charming, young New Zealand quintet) and members of their crew onstage for a cover of Pete Townshend’s “Let My Love Open the Door,” with guitarist Blake Sennett on ukulele.
In the process, Rilo Kiley has become more emphatically Jenny Lewis’ band. The diminutive singer has grown as a performer; dressed in a short, lemon-yellow shirt-dress (and a guitar that matches it) and cherry red knee socks, she’s Lolita rewritten by James M. Cain; on “Portions for Foxes,” she entices a boy by telling him she’s “bad news” and calling him “damage control for a walking corpse like me.” On “I Never,” a wonderful, R&B-shaded torch ballad, she brings the vulnerable power of Dusty Springfield or Leslie Gore.
Rilo Kiley opens up for Coldplay’s East Coast dates, including Madison Square Garden on Sept. 6. If the band continues growing at the present rate, it won’t be long until it’s the headliner.