One of the reliably intriguing aspects of Vladimir Jurowski's visits to the Philadelphia Orchestra podium is the difficulty of telling from the written program the reason for assembling these particular pieces. The "why" becomes crystal clear, but only as the program is played, as it did Thursday night when the orchestra's great bearer of artistic purpose remade the ensemble three times over before our ears.

Opening, it was an impressively tight new music ensemble. Then it was pared down to a lithe Mozart orchestra. The final incarnation of the night was an act of restoration - to the variously tender and powerful Strauss machine built by Wolfgang Sawallisch.

Jurowski may hear more Wagner in Strauss than Sawallisch did, but Also sprach Zarathustra is that kind of piece. Musicians looked depleted by the end of the concert, which demanded the kind of discipline to which they may no longer be accustomed. The Strauss was tightly controlled - and had the virtue of never sounding that way. Jurowski solved awkward moments of transition, such as the lifts between phrases in the glowing section of divided strings in "Of the Backworldsmen." Others may insert near-pauses. Jurowski, however, found micro hesitations, preserving a sweet rush of sound that brought tears. Longing, joys, and passions poured forth with the same freedom and momentum, incredibly focused but unstoppable as nature.

Julian Anderson's The Stations of the Sun (1998) arrived like a long overture: jumpy, high-spirited, veering back and forth between austerity and warmth. This was the orchestra's first time playing a work by the important English composer, and though at its most dense the piece became nearly impenetrable, it showed the ensemble's strengths.

Jurowski and the charismatic violinist Alina Ibragimova stripped Mozart's Violin Concerto No. 4 in D major (K. 218) of the silly sentiment that has settled upon it in four decades of being an FM radio standard. The ensemble, at a scant 30 players, made room for the Russian-born violinist's taut expressiveness, as well as sound shadings robust in the lower register, and an impressive pianissimo tracery no less sturdy for being so high. Ibragimova's playing isn't showy, but a boldly etched picture of individualism within the composer's intent.

Additional performance: 8 p.m. Saturday, Verizon Hall, Broad and Spruce Sts. Tickets: $10-$105. Information: 215-893-1999 or