Lyle Lovett might be the only musician who could perform inside a phone booth.

At his sold-out show Thursday night, the Texas treasure stood stock still, to the point of being stiff, with his legs together and his knees slightly bent as he played his acoustic guitar and sang in his plaintive tenor. Even after a 15-year career, Lovett still appears to battle stage fright.

Not that that stopped him and his eight-member band from putting on a top-flight show for the 1,908 people at Portland’s Merrill Auditorium. Lovett, whose beakish nose and comblike pompadour made him most resemble a rooster in a double-breasted suit, was a congenial host, bringing his songs to life through his informative introductions.

Lovett has never been one to follow convention, and that continued Thursday night, as he dedicated the bulk of his two-hour show to songs from his current CD, “Step Inside This House.” The double album is his tribute to Texas singer-songwriters he had grown up listening to and playing with, including Townes Van Zandt, Michael Martin Murphy, Walter Hyatt and Guy Clark.

These lesser-known songs might seem like a tough sell, but Lovett’s love for the music was contagious, as he animated them with a little history and a lot of humor. Although the songs belonged to others, Lovett made them his own.

Before playing Murphy’s never-recorded “West Texas Highway,” he explained onstage, “I’d heard him play it, then started looking for it on his albums. I finally learned it from a bootleg record. (A few seconds pause). I don’t recommend that.”

As a humorist, Lovett is the Steven Wright of popular music. Audience reaction was a beat or two behind his jokes. And much of his deadpan humor seemed spontaneous. Consider this introduction of David Rodriguez’s “Ballad of the Snow Leopard and the Tanqueray Cowboy”: “David Rodriguez was a lawyer who became a folk singer.” (The audience applauds.) “I didn’t know folk music was so popular up here. Anyway, I haven’t heard much of David lately, after he moved to Holland. I guess folk music is popular in Holland, too.”

Lovett continued his story, telling the audience of playing a club date with Rodriguez. While Rodriguez was playing, Lovett was standing at the back of the room, near a beautiful woman. “I was listening to him with my ears and listening to her with my eyes. I could see the song was really affecting her. She turned to me and explained, `He wrote that for me.’ [Pause.] So that’s how you do it.”

While the crowd enjoyed Lovett’s current songs, they reacted strongest to the handful of his hits, which he played about two-thirds of the way through the show, including “If I Had a Boat,” “She’s No Lady (She’s My Wife),” “Church,” “That’s Right (You’re Not From Texas)” and “I’ve Been to Memphis.”

A pleasant surprise was the appearance of bluegrass superstar Alison Krauss, who contributed harmony vocals on several songs, including “More Pretty Girls Than One” and “Texas River Song.”

Krauss, whose brother Viktor is Lovett’s bassist, looked lost without a fiddle in her hands, as she tightly grasped her hands behind her. But she and Lovett offered up a lovely blend.

Most of Lovett’s talented band added compact but meaty solos. This meant not only from such obvious choices as guitarist Pat Berguson and Mike Aldridge on Dobro, but also from cellist John Hagen and Viktor Krauss on stand-up bass.

All these elements combined in a warm, song-packed two hours on a cold fall night. Lovett will never be mistaken as a showman, but he sure knows how to entertain.