The Tanglewood Festival, arguably the most prestigious of the classical music summer encounters taking place on this side of the Atlantic, has several components: the Boston Symphony Orchestra concerts; chamber music events; rock, pop and jazz evenings. There is nothing though more important for the future of classical music making in this country than the Tanglewood Music Center Fellowship program, the BSO’s summer academy for advanced musical studies, founded by Serge Koussevitzky in 1940. TMC offers emerging instrumentalists, singers, conductors and composers the chance to study under the aegis of a faculty comprised of members of the orchestra and outstanding guest professors. It also encourages the young musicians to actively take part in dozens of performances all summer long. According to some estimates, 20% of the members of American symphony orchestras and 30% of their first chair players have studied at Tanglewood.

The first TMC public concert of the 2016 season was an exceptional one: a full evening of rarely interpreted Bach cantatas conducted by John Harbison, one of the most distinguished artistic figures active in the United States today. Prolific composer, recipient of the Pulitzer Prize and a MacArthur Fellowship, he has always tried to – in his own words – “reinvent traditions”. Harbison first conducted Bach cantata performances in 1958 and he has continued to do so regularly, presently being the principal guest conductor of the Emmanuel Music in Boston, an ensemble with a 45 years old tradition of presenting weekly Bach cantatas in a liturgical setting.

For the concert with his students at TMC, Harbinson picked four sacred cantatas which he didn’t present in any discernible order. One of them, BWV 163, Nur jeden das seine (To each his own) dates from the Weimar period and the other three are part of the annual cantata cycles that Bach composed in his first years as Thomaskantor in Leipzig. The texts, related to the prescribed reading from the Gospels, are a mixture between direct quotes from the Bible and paraphrases by different authors, some of them known, other anonymous.

Harbinson used a small string orchestra augmented when needed by a pair of oboes or oboes d’amore and a single horn. He approached the music with awe and humbleness, with a keen desire to guide his young disciples and the public on a path of discovering the many ways in which Bach’s music speaks to every listener. The members of the ensemble responded to his modest and exact gestures not only with the expected enthusiasm but also with a precision of execution that one would not expect from inexperienced musicians that have played together for such a short time.

For a cantata written for the second day of Christmas, Selig ist der Mann (Blessed is the man) lacks a celebratory spirit. Three of the four arias are in a minor key and quite gloomy in character. It is one of the four cantatas that Bach structured as a dialogue between Jesus and the yearning Soul and the solo violin (Jordan Koransky) beautifully suggested, during the last soprano aria, the Soul’s journey from fear and uncertainty into the arms of Jesus.

The second piece on the program, Du Friedefürst, Herr Jesu Christ (You Prince of Peace, Lord Jesus Christ) BWV 116, is structured in six movements with a marked contrast, exquisitely rendered by the TMC ensemble, between the outer, optimistic, orchestral settings and the inner movements reflecting the anguish of the sinners awaiting judgment. It is also to be noted that BWV 116 is one of the few among the 200 extant Bach cantatas featuring a vocal trio – soprano, tenor and bass – accompanied only by continuo in the elaborately contrapuntal aria “Ah, we recognize our guilt”.

Two more “concertos for voices and instruments” followed after intermission. The shorter, austerely scored cantata BWV 163 (Nur jedem das Seine) featured two of the evening’s really outstanding vocal interprets, soprano Bahareh Poureslami and mezzo Quinn Middleman, singing here as a duet. The most remarkable music was though the aria “Let my heart be the coin”, convincingly sung by baritone Dominik Belavy, with an unusual accompaniment of just two obbligato cellos and continuo.

Finally the most elaborate music came at the end: the cantata in two parts, BWV 187 Es wartet alles auf dich (Everything waits for You) with free polyphony embedded in the instrumental music and a marvelous dialogue between soprano (Adriana Velinova) and oboe (the admirable Kristin Perry).

If the instrumental ensemble performed without fault, the vocal soloists, coached, according to the program notes, by such luminaries as Dawn Upshaw and Sanford Sylvain, were not all at the same high level, some of them failing to quite prove their understanding of the particularities of singing Baroque music.