In his informal pre-concert talk on December 5, New England String Orchestra (née Ensemble) conductor Federico Cortese took the view that a work written with one medium in mind can be illuminated, and even sometimes best presented, by transferring it to another medium. That was his story, and he stuck to it as NESO and soloists Robert Spano, piano and Nadia Sirota, viola, performed works by Janácek, Bach, Bermel and Beethoven at Jordan Hall. Cortese made his case as forcefully as possible, and if it was more persuasive in some instances than others, it was not from any lack of conviction or effectiveness on the players’part.

Cortese opened with Janácek’s Idyla, JW 6/2, an early suite (written in 1888, when the late-blooming composer was 34). The transcriptive nature this piece was, Cortese admitted, a bit of a stretch: Janácek did not play any string instrument, and probably composed this work at the organ, where he was generally to be found in those years. The string writing did not, therefore, sit as comfortably to play as one might expect of an experienced performer (although, as Cortese also admitted, Schubert was an experienced player whose string writing could be awkward). The work’s six movements are all informed by Czech folk and dance idioms, which furnishes a link to the idea of the Baroque suite, although compared, say, to Grieg’s Holberg suite, there were no references to older dance forms. Most of the movements were in simple dance-like ternary forms (one — though not the first — was an abbreviated sonata form), and the harmonies and some of the melodic gestures echo Dvorák (who was present, according to the uncredited program notes, at the premiere). Still, there were some delightful and original features to the music: one movement’s main theme was in a lilting 5/4 meter, an early example several years before Tchaikovsky’s Pathétique Symphony; and the slow movement’s theme was in compound fours with quintuplets on accented beats and some pickups. The performance by the 20-member ensemble brought out all the work’s charm, with occasional hints of darker recesses. Tempi were well chosen, although one movement marked Moderato seemed rather slower than that, and everybody’s tone, intonation, and ensemble work could not have been better.

J.S. Bach’s D-Major Harpsichord Concerto, BWV 1054, was a transcription by the composer of his violin concerto in E, BWV 1042. Thus, apart from transposing the key (because, we are told, many harpsichords of the day lacked some the necessary high notes), the only re-imagining needed was in the solo part to flesh out the implications of the single string line. Both versions are among Bach’s best-loved instrumental works, with the tunes of the first and third movements well embedded in Western cultural consciousness. What really amounted to a second transcription was the decision by Spano, Music Director of the Atlanta Symphony and former BSO Assistant Conductor, to play this on a piano rather than a harpsichord. There are several decent justifications for this: Bach’s music is practically indestructible in any medium or sonority; we all learn to play Bach on the piano, and before Wanda Landowska, everybody played it in concert that way; the strings of NESO are not period instruments, so they can withstand the louder noise the piano makes; and so on. There is thus nothing a priori wrong in doing it as Spano did; one need only judge the result.

The interpretive result from soloist and orchestra was good. The strings were top-drawer (we must say that this whole concert was the best-sounding of any NESO/NESE performance we can remember); Cortese led with vigor, lilt, and grace (a bit too fast for our taste in the first movement, but no detail was slighted by it), and Spano played with great gusto — he loves the piece. Where we were less than fully satisfied was with his passagework, which was too often unclear, and his touch. So OK, here was a full-sized concert Steinway, at full stick (a mistake, as it happened), so it was incumbent on the pianist to go a bit easy to preserve balance. We fully acknowledge, from being on the keyboard side, that he appeared to try — he didn’t linger, he mostly kept his wrists up. It wasn’t enough. In the excitement of the moment, there was just too much force applied, and the piano overwhelmed. File this one away in the “lessons learned” compartment.

Derek Bermel, whose work has only occasionally made it to Boston ears (in the last five years, BMOP, the Guarneri Quartet on tour, and Chameleon Ensemble have performed him), is a New York-based composer and clarinetist who has been drawn to ethno-musicological influences. His Soul Garden for viola and ensemble was written for Paul Neubauer and the Chamber Music Society of Lincoln Center in 2000. The original instrumentation was for solo viola plus “cello quintet,” thus creating, in one implementation, a double string trio. The work, however, is clearly concerted; the viola takes the role, according to the composer’s conception, of an alto vocalist in a gospel-style church service. Much of the work involves call-and-response effects, with one of the cellos taking the latter part, with occasional commentary from a solo violin. The scaling up of the instrumentation was a result, we were told, of a request from an Australian performer, who made his own arrangement that Bermel then edited before approving it. Therefore, this represents a hybrid transcription process: it wasn’t the composer’s idea, but the realization had his participation and approval.

As to the result and substance, we can say that Soul Garden is a very attractive piece worth hearing again. The main tune, presented straightaway by the solo viola, is tonal, pentatonic and microtonal all at once, with gospel and klezmer vying for prominence. The opening, solemn and keening, moves up in pitch, intensity and volume to a big climax, followed by a cadenza, another climax, and a winding down. Most of the thematic material derives from the opening.

Nadia Sirota, whose day job is actually a night job, hosting the overnight program on WNYC, is the latest and by no means the least of a musical family that includes composer father Robert and violist brother Jonah of the Chiara Quartet (if you think your kids are overscheduled, consider this family dilemma: dad came to Boston to hear Nadia, while mom was in New York hearing the Chiara, on the same day). Ms. Sirota was a highly engaging and emotionally engaged soloist, with a rich big sound and impressive technique — microtones making exact change in cents — and a foot that wanted to stomp out the “amens.” Her calls were well answered by NESO principal cellist Joshua Gordon and concertmaster Heidi Braun-Hill. Cortese and the rest of the ensemble gave excellent support, notably where coordination of microtonal passages was required.

The biggest test of Cortese’s thesis regarding transcriptions came in the closing work, which was Gustav Mahler’s transcription (nowhere credited in the program!) of Beethoven’s Quartet No. 11 in F minor, op. 95. The op. 95, though written in 1810 and thus technically not attributed to Beethoven’s late period, is nevertheless one of his kookiest creations. In it he compresses to nearly black-hole density ideas of radically different character — in his pre-concert talk Cortese mentioned that the entire first movement is shorter than the development section alone of any of the Razumovsky quartets. Beethoven initially did not want this plainly experimental work to be publicly performed (obviously, he changed his mind inasmuch as he published it four years later), and the challenge for any public performance is to provide some means of communicating Beethoven’s speculations in a way that renders them intelligible to a general audience. Enter Mahler, who never wrote chamber music in his maturity, but whose prowess as a conductor perhaps tempted him to see if he could scale up this curmudgeonly prototype without dulling its raw energy and edginess. We have always entertained reservations about these enterprises conducted without auctorial sanction — the orchestra version of the Grosse Fuge, for example, often lacks the bleeding edges that come with the quartet version. Cortese had to go a long way to carry the burden of proof, and he of course knew it and knew exactly where the issues would be.

The NESO players came through like champs; they maintained taut control, sharp attacks, perfect articulation; the musical ideas were clearly limned and communicated. And yet…in the first movement, what was gained in power was lost in edge. The score after the first quarter stood at Beethoven 1, Mahler 0. The “slow” movement (another of Beethoven’s Allegretto slow movement substitutes) was much more successful. The more lyrical music seemed to benefit from the fuller sonority (think Barber’s Adagio for Strings, also a string quartet transcription). The wild-man scherzo was also well, um, strung out, the power here being more persuasively deployed, and the attached finale too was gripping. Cortese held everything in suspense at the grand pause that precedes the delirious F-Major coda. Was Beethoven, at the end, telling us, “just kidding”? The overall result was a qualified triumph, well worth the hearing and thinking about.

Vance R. Koven studied music at Queens College and New England Conservatory, and law at Harvard. A composer and practicing attorney, he was for many years the chairman of Dinosaur Annex Music Ensemble.