'This is a song by Elliott Smith," Seth Avett announced with complete sincerity while standing next to Jessica Lea Mayfield on stage Saturday night. For a duo touring in support of their forthcoming album, Seth Avett and Jessica Lea Mayfield Sing Elliott Smith, such an introduction before each song should have been overkill.

But Avett's collaboration with Mayfield breathes new life into Smith's catalogue of forgotten gems. With each introduction ("This song is by Elliott Smith and is called 'Between the Bars,' " or "We're going to play you another Smith tune; this one is called 'Memory Lane' "), the catalogue of somber waltzes by a man who took his own life more than a decade ago was resurrected.

Seth, the youngest of the Avett Brothers, and Jessica, the 25-year-old songwriting prodigy with a space twang, bonded over their love of Smith and began work on an album of cover songs in 2011. Due to their separate yet equally busy touring schedules, the two met up sporadically in houses, hotels, and recording studios across the country and recorded 12 of Smith's songs. They have clearly left an impression on both artists, emotionally and lyrically.

Mayfield, in a black, sequined minidress, and Avett, with a nonstop jug band bounce, were joined by upright bassist Paul Defiglia at the Keswick Theatre for a 90-minute set with minimal banter. The evening featured a mixture of the Smith tunes, songs from their respective solo projects, and songs that show a direct lineage to Smith and his own musical influences. On songs like "Ballad of Big Nothing" and "Pitseleh," the duo alternated lead vocals and harmonies, revealing a rich texture to songs that originally had multitracking layers of Smith's papery voice. Each song grew beyond its original potential, still recognizable, but with new ownership.

Both Avett and Mayfield have powerful voices that carry the words and melodies of familiar songs to new levels. In a near-perfect interpretation of Bob Dylan's "Just Like a Woman," Avett warbled, whispered, and wailed, Mayfield sang back-up, and an enthusiastic audience member screamed, "Yeah!" at the top of his lungs in support of this spirited collaboration.

The only distraction of the night came from an unfortunate piece of scenery that dwarfed the stage and added clutter and confusion to music and musicians better served by a bare stage and a velvet curtain. The concert was performed in a "kitchen" with unsightly wallpaper, a refrigerator, a table, and an electric tea kettle on which Mayfield boiled water upstage right, while Avett sang Smith's "Angeles."

Despite the cluttered stage, the evening was a celebration of Smith and his posthumous legacy. As Mayfield and Avett sang so genuinely: "It's just a fond farewell to a friend."