Along with his famous shock of gray hair, conductor Benjamin Zander is also known for his enthusiasm, eloquence and fearless dedication to his orchestras and their individual players. Zander at 84, and with more than 50 years at the podium, is still the kind of teacher and leader who inspires, and expects, musicians of whatever age who come into his orbit to play better than they thought they possibly could.

“Shaping Future Leaders Through Music” is the credo of the Boston Philharmonic Youth Orchestra, which Zander founded in 2012 under the auspices of the Boston Philharmonic — which Zander also founded, back in 1978. The 120 musicians who make up the BPYO at any given moment range in age from 12 to 21, and while some of the orchestra’s stated aims for these enthusiastic and very talented young players might sound extra-musical — “leadership development that strengthens communication and deepens the human experience,” for example — music is still its forte.

Zander’s Boston fans are accustomed by now to this pied piper of youth orchestras taking on the most demanding repertoire to the pleasure and amazement of local audiences. On Wednesday, BPYO again delighted and maybe even stunned Symphony Hall patrons with its orchestral virtuosity and ability. It was an eye- and ear-opening experience, especially for anyone hearing this ensemble for the first time. No amount of stellar reviews can really prepare you for witnessing this youth orchestra live; it is a breathtaking experience.

Closing out their 11th season ahead of a tour in South Africa, the Youth Philharmonic performed a single 90-minute symphony: Mahler’s 2nd, a.k.a “The Resurrection.” The Symphony Hall stage extended several rows into the floor to accommodate the extra forces required by this monumental score. The upsized ensemble on Wednesday included a youthful, if not strictly “youth,” contingent: soprano Maria Brea, mezzo-soprano Jennifer Johnson Cano, and Chorus pro Musica — music director, Jamie Kirsch.

Zander strode on stage to enthusiastic applause and then talked about Mahler’s five-movement epic, which Zander said rewards listeners who come to it “with an open heart.” He then set about proving his point, spurring everyone on stage to play, and sing, like their lives depended on it.

Mahler’s 2nd, which premiered in 1895, was a foundational moment in his career. If this work had been a vinyl record, anywhere you dropped the stylus would sound like Mahler. Everything he’s known for was there — the brilliant orchestration, the Viennese charm, and his trademark irony, pathos, and boisterousness, as well as a preternatural contrasting moments of calm.

Zander, indefatigable as ever, took less than the score’s recommended five-minute pause after the lengthy first movement. What was striking was just how good the players were, section by section, and not just the principals. Although they, too, were remarkable — among them Grace Helmke, flute; Anna Choi, oboe; Tristen Broadfoot, clarinet; and Andrew Salaru, bassoon; all of the brass; and Shaylen Joos, harp.

You could have closed your eyes and imagined this was, in no way, a youth orchestra, These players gave it their all, and their all was extremely impressive. They played with sophistication and confidence, and their ensemble work was consistently first-rate.

Brea — making her Boston-area debut — and Cano were likewise stellar, and Kirsh’s chorus also rose to the occasion with exemplary finesse. Their heaven-storming last pages — given uplifting support by tubular bells and Symphony Hall’s organ — built inexorably to the close of an overwhelming experience, with Mahler’s transcendental vision of the afterlife fully realized by these extraordinary young musicians.

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