Concertgoers familiar with conductor Louis Langree’s nearly decade-long stewardship of New York’s Mostly Mozart Festival know him to be a perceptive Mozartean. His accustomed interpretive profile in the composer’s music — buoyancy and suave finish in the orchestral texture, sparkling and affectionately turned phrasing,and a keen sense of Classical proportion – were reliably in place in shapely performances of Mozart’s “Paris” Symphony and his Third Violin Concerto with the Baltimore Symphony at Strathmore Hall on Thursday.

Violinist James Ehnes proved an ideal match for the Apollonian approach Langree took to this sunny concerto score by the 19-year-old composer. Ehnes’s tone is notably beautiful, with its pitch-perfect attack, roundedness and consistent gleam. This artist, too, knows how to make individual phrases memorable within long, cogently thought-through musical paragraphs, giving the kind of light-filled reading that made one want to hear him in all five of the Mozart concertos.

After intermission, an all-Debussy second-half revealed a very different, but even more compelling, side to the conductor. Where Langree’s approach to 18th-century music emphasizes proportion and musical architecture, his Debussy surrenders gloriously to shifting color and narrative flow. His “Prelude to the Afternoon of a Faun” was uncommonly languorous and delicate, its phrases wafting up and swooning back down into a shimmering orchestral fabric. “La Mer” was just as vivid — all glinting sunlight and elemental surge, with Langree masterful in teasing out the ebb and flow of dovetailing melodies and timbral hues. This was some of the most sensitive and alluring Debussy I’ve heard, and the orchestra played it marvelously.