At Symphony Hall on Friday night, Benjamin Zander led the Boston Philharmonic in works by Mahler and Schubert

The Boston Philharmonic returned to Symphony Hall on Friday night with a hauntingly beautiful program that seemed to invite reflection on the very notion of completion, and perhaps, its impossibility.

The night began with Schubert’s “Unfinished” Symphony. Exactly why Schubert left this work incomplete is a mystery that remains unsolved to this day, despite the rigorous sleuthing of generations of musicologists. The composer’s life was indeed cut short by syphilis — he died in 1828 at age 31 — but the two existing movements of this work date from six years earlier.

Conductor Benjamin Zander approached the score on Friday night with the poise and lucid insight of a veteran interpreter. His reading was surely paced, with a keen sense of the work’s dramatic arc and a deep appreciation for its endless flow of lyricism. The cellos unspooled the first movement’s famous theme with a warm songfulness and a graceful sense invitation. Overall the orchestra sounded at the top of its game.

Mahler’s song of the earth, “Das Lied von der Erde,” made up the second half of the program. This setting of selections of ancient Chinese poetry in German translation dates from the final years of Mahler’s life, and it presents the composer at the height of his artistic powers while at the same time possessed of a sometimes brutal sense of existential honesty. On Friday night the opening movement, “The Drinking Song of the Earth’s Sorrow,” danced at the edge of wildness.

Peggy Pearson’s wisely knowing oboe made the following poem, “The Lonely One in Autumn,” a study in the melancholy sublime. In truth the night was an exceptional outing for the entire core of the orchestra’s woodwinds, including Lisa Hennessy (flute), Rane Moore (clarinet), Mary Kay Robinson (piccolo), and Rachel Jusczcak (bassoon).

Tenor Stefan Vinke sang with clarion strength and tonal focus, yet vocally speaking, the night belonged to Dame Sarah Connolly. Sensitively partnered by Zander and the orchestra, she conferred on the glowing lines of “Der Abschied” — Mahler’s glorious final song of farewell, the one we are waiting for — an unsurpassed depth of meaning and expressive radiance. This particular song brims with that true Mahlerian sound, the special strain of consolatory beauty that the composer bequeathed to his own posterity, a simultaneous acknowledgment of life’s tragedy and its wonder, twinned insights that somehow do not cancel each other out but rather flood this music with an ineffable sense of the real.

Perhaps it is that very sense of honesty that makes “Das Lied von der Erde” feel, in its own way, as unfinished as Schubert’s symphony, as unfinished as Mahler’s art, and as unfinished as his life, which ended at age 51, when he was midway through his Tenth Symphony.

Friday’s performance did at least complete the Boston Philharmonic’s season, which ended with the hall on its feet, expressing gratitude.

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