At Leader Bank Pavilion, songs in the key of Elvis

Elvis Costello and Imposters drummer Pete Thomas perform at Leader Bank Pavilion.Ben Stas for The Boston Globe/The Boston Globe

The two solid hours that Elvis Costello and his band, the Imposters, put in Monday night at Leader Bank Pavilion had almost all of the ingredients of a memorable or even spectacular Costello show.

Part of what’s billed as “The Boy Named If & Other Favorites” tour, it certainly had ample servings of both. Costello didn’t get to 2022′s “The Boy Named If” until midway through the evening. But he offered up five of its songs, with “Magnificent Hurt” and “Farewell, OK” in particular illustrating how evocative the album is of early Elvis.

Fittingly enough, and true to the tour’s titular promise, the rest of the setlist was dominated by favorites drawn from that period; “Armed Forces,” “My Aim Is True,” and “This Year’s Model” accounted for 11 of its 23 songs. But like the new album, those songs weren’t simple reprises of what came before. Costello interpolated an extended “Invisible Lady” into “Watching the Detectives” to marvelous effect, and concert staple “Pump It Up” was simply rocket-fueled. He wandered off the favorites path as well, for the hep-cat noir vibe of “Hetty O’Hara Confidential” (driving home the song’s line “now everyone has a megaphone” by using one to deliver it), and for a muscular run-through of his song “I Want You,” which came with a sly, passing reference to the Beatles’ song of the same name.

Long-running supporting outfit the Imposters were as tight and as rocking as ever, and they were augmented by Austinite Charlie Sexton, whose guitar work, now ferocious on “What If I Can’t Give You Anything But Love?,” now delicate on closing song “Alison,” was a highlight of the evening. There were guests, both expected and unannounced, as well. It was no surprise to see Nick Lowe, who played an opening set accompanied by Los Straitjackets, return to the stage for a pair of songs with his longtime fellow-traveler, including, naturally, the song that has done much for Costello (and, via royalties, for him), “(What’s So Funny) ‘Bout Peace, Love and Understanding?” As for the unannounced, it was singer Nicole Atkins (who opened some of earlier shows on the tour) joining Costello to lend her magnificent pipes (and her sass) to some back-and-forth on “Still too Soon to Know” and to five more songs.

As ever, Costello the witty raconteur was in fine form, with allegedly autobiographical recountings that included a backdrop to the song “Penelope Halfpenny.” His skills as a guitarist were also very much on display, nowhere more so than on the jagged, punctuating lines he added to “I Want You” and “(I Don’t Want to Go to) Chelsea.”

Given all that, what was missing? To put it simply, it had to do with Costello’s singing. From opening song “Accidents Will Happen” on, finding the same key as his band was in seemed to be a recurring problem, and it reached a nadir during what should have been a high point of the show, the songs he sang with Atkins (especially “I’ll Wear It Proudly,” which threatened to go completely off the rails). When Costello was hitting the mark vocally, the show was all it could be; when he wasn’t, it was impossible to ignore.

Stuart Munro can be reached at [e-mail].

ELVIS COSTELLO AND THE IMPOSTERS

With Nick Lowe and Los Straitjackets. At Leader Bank Pavilion, Monday