Sunday afternoon, January 22^nd with the Boston Artists Ensemble at Trinity Episcopal Church in Newton meant having the rare opportunity of hearing one of Mozart’s last string quartets (one that he troubled over) and one of Bartók’s six quartets (one that takes instruments further into idiomatic techniques and musical expression). Certainly, Bayla Keyes and Peter Zazofsky violins, Kathryn Lockwood, viola, Jonathan Miller cello, took on some of the most difficult quartets in the entire repertoire. Just about everything was under control in their somewhat daring two-part program pairing of String Quartet in B-flat, K. 589 and String Quartet No. 4, where they spoke with  musical eloquence and uninhibited dialect.

According to Steven Ledbetter, the distinguished annotator and BMInt reviewer, well known to Boston concert-goers, “It is not clear precisely why Mozart found the composition of these string quartets troublesome…it is known that… K. 589 made use of material that he had written and then discarded almost a decade earlier. Perhaps he found his natural flow of musical ideas disrupted by his temporary feelings of self-doubt and required the artificial impetus of pre-existent material in order to get himself started.”

Listening to the Quartet in B-flat in this perspective reinforced my own sense that this quartet is one of Mozart’s most wondrous: cut-ins, harmonic parallelisms, abundant textures, polyrhythms, expanded cello writing, and meatier interior movements. The Boston Artists Ensemble (BAE) never appeared reluctant “to speak the truth” — what was in their hearts and spirited bows. Expression, at once formal and personal, was pure joy to experience.

While they obviously knew what and when and how they were to sound a note, I felt something in the moment often taking place, a good dose of expressive improv, if you will. And with that, we all know, comes danger — the kind that makes a live performance alive. Certain missed tunings and fluffs there were, but very few and almost all of them in that “danger zone.” Mozart played out this way, this human way, is quite a remarkable way for professionals of this high caliber.

Before performing Bartók, BAE members talked about and demonstrated the quartet’s themes, math, Golden Mean, arch form, dissonance, “Bartók plucking,” and counterpoint, all for the good; I was able to glean more about their thinking of the Hungarian’s art-and-folk music. There is not a single doubt, judging both from their comments and performance, that the gifted and experienced members of BAE had one big passion going for the 20th century highly idiomatic String Quartet No. 4.

But their passion was too much for me. Forte markings in the score became fortissimo. The light and feathery second movement with mutes on the strings became too viscerally charged for any kind of relief that the composer surely had in mind. More passion from the cello in the third movement further illustrated BAE’s outwardly passionate urges. Ultimately, areas of repose and climax became increasingly difficult to delineate mentally, much less emotionally. Yet, that they took their position on this music is a big plus, just as it was with the Mozart.

I like their taking positions, though I might not go along with them. Why not catch these fine musicians with a big dash of daring and decide for yourself? Their next concerts are in March and April, which you can find at their website here.

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