With half a century of experience between them, it comes as no surprise that Ted Leo and Aimee Mann know how to engage an audience. What cannot be chalked up to experience is their natural chemistry, exchanging playful jabs and awkward jokes, and a perfect pairing of vocal talent. If they weren’t locked in tight harmonies redolent of searching country drives through Kodachrome vistas, they were trading lines of verse back and forth, where one voice melted seamlessly into the other, as if they were not just trading lines, but sharing vocal cords. With indie rock auteur Nick Diamonds opening, the evening was a solid display of vocal and voice.

Diamonds’ intimate sit-down set began a capella, performing a cover of the Zombies’ “The Way I Feel Inside,” joined by fellow Islands multi-instrumentalist Evan Gordon on keyboard for an impressively faithful cover. The rest of the set followed suit, the duo balancing ’60s sheen with Diamonds’ sweetly commanding vocal that carried rich melodies over ever-moving, inventive chord progressions too fragile, too complex to be caught anywhere near today’s cut-and-paste mainstream. Even a song he introduced as “new” could have just fallen out of a weathered record sleeve and into his echo pedal. The soulful set was oddly interrupted by the appearance of “Buford,” a wigged, maroon-sweatered phantom claiming to haunt the El Rey, who came out to accuse the pair of sucking at rock music before leading them in a version of “Voices Carry” that sounded as if it were spliced with the DNA of “Monster Mash.”

The Both’s set got off to a rocky start when Leo’s guitar emitted an ugly crackle the moment he picked it up. A replacement was tracked down halfway through the set, only for him to realize that it was the cable all along. They seemed to revel in the self-deprecation sparked by the tech problem, never taking themselves too seriously, like two faithful celebrants of chaos. At times more like a comedy duo than two well-traveled artists, it took them several minutes of what felt like an improv performance to get around to playing the first song. But with the sassy opening chords of “The Gambler,” the abrupt transition from comedy to emotive display was impressive and stunning.

Leo’s guitar work seems to have actually tightened since the recording, although he still knew when to let things fall apart. Mann’s even-keeled, soporific voice has found a valuable partner in his sexy, scorching shreds, which give a welcome shot of dirt to arrangements that can sometimes be a little too clean, too pretty, too safe. The standout performance was “Milwaukee,” a catchy anthem that they buried deep into their 14 song set, giving the audience one last jolt before bringing things to a close. The night ended with a soaring version of Mann’s 1985 hit “Voices Carry” and a Thin Lizzy cover, “Honesty Is No Excuse.”

Set List:
Volunteers of America
No Sir
The Inevitable Shove
Pay For It
You Can’t Help Me Now
Save Me
Lonsdale Avenue
Hummingbird
Bedtime Stories
Milwaukee
The Prisoner
Goodbye, Caroline

Encore:
Voices Carry
Honesty Is No Excuse