Rounds of praise are due a brand new duo that made its Boston debut last night at The Roxbury Latin School. Guitarist Jason Vieaux and accordionist Julien Labro each revealed remarkable levels of individual artistry, and the chemistry between them openly and fully communicated. These along with other elements conspired to bring about that ideal situation where we find ourselves completely engaged, where we find ourselves not just being shown the way, but discover ourselves being a very part of learning along the way. Vieaux and Labro are Artists-in-Residence at Roxbury Latin.

Both Vieaux and Labro refreshed the often staid concert stage with uncommon graciousness, the kind of which comes from an unassuming nature both rare and welcome. Their amply appreciating their listeners as much as their making music together sets the duo’s mien apart from today’s common classical practices of performance. They love what they do and the audience finds itself very much a part of that joy. Labro’s way of putting it last night: “we are thankful to be playing before a small and intimate crowd who knows how to listen.”

The mid-size Smith Theatre with steeply terraced rows of wooden pews (with abnormally high backs and furnished with comfortable cushions) helped in projecting infinitesimally delicate sounds from Vieaux and Labro. Though Vieaux amplified his guitar, it was just enough to give it presence yet without interfering, to any noticeable degree, with the instrument’s natural acoustical integrity. Flipping his sheet music on the floor as he often went from page to page drew Vieaux’s own comment, “Who made this mess?”

Purposely integrated and ever-changing spectra figured in all the pieces on the well-planned program featuring Astor Piazzolla’s four-part Histoire du Tango as bookends. Bordel 1900 and Café 1930 reexamined nostalgia and flair with which the tango is associated and seen through the lens of a classically informed composer.  In the second set, Nightclub 1960 and Concert d’Aujourd’ hui more bustle and images of a teeming life emerge, especially in the latter that was composed in 1984 or 85.

Isaac Albéniz’s well-known Sevilla transmuted from piano to guitar lost nothing, rather, unquestionably gained much in the picturesquely and idiomatically conceived solo rendition from Vieaux. Albeniz’s popular Asturias weighed in on the second half of the program. Remembering the piece well from umpteen interpretations on the guitar, I wondered what it would be like in the hands of Labro in his own arrangement for solo chromatic button accordion. It was amazing — I cautiously choose this overly used word — both in sound and sight, his upper body shaking to the rapid movements of the bellows; this was another something new to me. Selections from Radamés Gnattali’s Suite Retratos ­underscored why being at a live concert can mean so much more than listening to a CD.

The duo swept jazz guitarist-composer Pat Metheny’s Antonia with tenderness and speed-driven improvisation, older, more worn phrases but fun to hear on the hybrid accordion-harmonica type instrument (I cannot remember its name). On the other side of the program was Leo Brouwer’s sinewy, serious Très Danzas Concertantes. The dynamic duo, with arranger Labro acting as orchestra on his accordion, lifted the harmonic treacheries (that bog the piece down) into a state of sonorousness.  I still miss the point with these dances, I did not, though, regret hearing them, that being due to infinite love both musician’s give to their playing.

Their encore was the 80s hit “Everybody Wants to Rule the World” from Tears for Fears, the duo deciding to give the song a try after watching the presidential debate on TV. Crossing genres and audiences is what these two do and do superbly. We should also be grateful to the Claire Berman Artist-in-Residence Fund for making this thoroughly enjoyable and engaging performance possible. Students, who will be meeting with the duo today, will also be discovering much, much more than music.

What did we discover? The bandoneón, which Labro played in the Piazzolla, is not originally from Argentina but was invented in Germany to serve as an inexpensive alternative to the church organ. Piazzolla studied with Nadia Boulanger, the famous 20^th century pedagogue, who urged the Argentinian to continue with his interest in the tango and become one of its voices, which, as it turns out, he did in a very big way.

David Patterson, Professor of Music and former chairman of the Performing Arts Department at UMass Boston, was recipient of a Fulbright Scholar Award and the Chancellor’s Distinction in Teaching Award. He studied with Nadia Boulanger and Olivier Messiaen in Paris and holds a PhD from Harvard University. www.notescape.net