Where to begin?

You may know that Elvis Costello is in the middle of a residency at the Gramercy Theater on East 23rd St. The theme is 100 songs in ten nights although as he said last night, it’s really 200 songs. Ten songs per night — all different — are printed on a card handed out to the audience. Then 10 more songs are guaranteed, also each night all different from his stunning 45 year catalog.

In other words, you may shout out “Alison”! or “Red Shoes”! as one lout did constantly last night but you’re not going to hear them unless you’re there on the right night. Sorry. Costello is a little like Ralph Fiennes in “The Menu.” He’s serving delicacies in his own order and his discretion.

Last night, not only were we happy to receive the 10 song main menu that included “45,” “Black and White World,” “God’s Comic,” and “Stella Hurt,” but also Burt Bacharach’s “Mexican Divorce” originally recorded by the Drifters), the rarity “Radio Soul” (the precursor to Costello’s hit “Radio Radio,” and “Mr. Feathers,” from his underrated “Momofuku” album. There were none of the hits, and it didn’t matter.

But when Costello, who played guitar and accompanied himself on piano, had completed 18 songs in one hour forty minutes, he had a surprise for the audience. He presented — with musical conductor Rob Mathes on piano and a group of eight Broadway singers — seven songs from the musical version of “A Face in the Crowd,” the Andy Griffith movie from the 1950s. Costello has been on this project for a decade, and hopes to bring it to the stage soon. He’s sung some of the songs in the past, but never realized in this way, all together, with a cast.

The good news — there is only good news — that “A Face in the Crowd” is ready for a workshop. The songs are terrific, especially a new one no one had heard before called “He Makes My Water Boil.” Hearing them all together was an unexpected treat that sent the intimate audience up on their feet. A standout was “Burn the Paper to the Ash” sung with Rebecca Lovell of Larkin Poe, a roots American sister act that was nominated three years ago for a Grammy and deserves much wider attention. Lovell’s voice has rich twang that added to Costello’s melodic turns.

Who knows what will happen to this new musical? It needs to be in the New York Theater Workshop, or a place like that, even in a concert form. Like David Byrne and Sting, Elvis Costello has a place in musical theater.

As for the rest of the show, these choices each night reflect the depth of Costello’s catalog. The wordplay of the songs in this setting becomes all the more important, so does the composition. There’s a lot going on in every Elvis Costello song, which are usually beautifully produced with his bands either the Attractions or Imposters, etc. Last night, with just Costello playing them (other shows feature either the Imposters or just master pianist Steve Nieve) songs like “Mr. Feathers” took on new life. “Alison” and “Red Shoes” weren’t missed.

Every night at the Gramercy has a theme, intentional or otherwise. Costello opened by indicating that “vaudeville” was the idea for the night, and that it was all about show business. But there was a lot spoken and sung about his late father and grandfather, each talented musicians. There was also a lot about Costello’s collaborator and mentor, Burt Bacharach, for whom he is grieving right now. The spirits of all three hung over the and gave it gravitas and pathos.

In the audience: Mike Myers, who featured Elvis and Burt in “Austin Powers,” hit TV comedy writer Eddie Gorodetsky, also Greg Geller, who signed Costello to Columbia Records in 1977. Geller’s wife, Hope Antman, was in charge of publicity then at the label. They told me they were there in London at Columbia Records’ convention when Costello, 22, wandered around outside playing his guitar with a small amp hung over his shoulder. The rest is history. Four decades later, Costello is still going strong, a master in many genres of music, with no end in sight.

What a night! If you can get in to the Gramercy before the run is over, then do so without fail. Otherwise, Costello will appear with the Imposters at the Capitol Theater in Port Chester, New York on March 3rd.

PS Every night ends with Costello’s cover of Nick Lowe’s “What’s So Funny About Peace, Love, and Understanding.” With Mathes, Lovell, the singers, et al — and no drummer — the song kind of levitated the audience, everyone sang along. As a grace note, the audience heard Dionne Warwick sing “What the World Needs Now” over the sound system.