★★☆☆☆/★★★★☆

The opening bars of this live performance assert that the Philadelphia Orchestra owns these works. The orchestra eases into the second symphony like an Olympic swimmer into a public pool, totally in its element, fearless of hazard or challenge. The strings are silken, the woodwinds ethereal. Then it all goes choppy.

He makes fussy adjustments, holding the orchestra back when it needs to surge

The Philadelphia Orchestra was involved with Rachmaninov from his arrival in America as a refugee in 1918, to his death 25 years later. Its music directors, Leopold Stokowski and Eugene Ormandy, championed his works and invited him to play them. The third symphony, his first important exile work, was a Philadelphia commission, poorly received at its premiere.

So what’s the problem here? The present music director, Yannick Nézet-Séguin, gets in the way of the music. In the long melodic lines of the symphony, he makes fussy adjustments, holding the orchestra back when it needs to surge, intruding excessively into an otherwise immersive experience. The great Adagio tune barely gets to breathe. Comparisons are invidious, but there is no shortage of conductors on record who know when to hold back — Ormandy, Pletnev, Jansons and Svetlanov, to name just three.

Dreading what might occur in the third symphony, which has less instant appeal and has defeated some of the best time beaters, I was thrilled to hear a brilliant performance, high on conviction and energy. Overusing the brass after a long dry spell, Rachmaninov needs to be delicately handled in this symphony — and Yannick does just that. The opening Lento is elegantly phrased, and the overlong finale is redeemed with exquisite solo episodes. The Philadelphia Orchestra has not sounded this sparkling since the Muti years.

The Isle of the Dead, not a happy place, is also gloriously done and without a trace of sentimentality. Like sports stars, you can never guess when Yannick is going to be on form. His inconsistency is just on the right side of the equation to keep you coming back for more.