Jordan Hall at the New England Conservatory. Packed. Each seat taken, people sitting in the aisles on the steps. (Those empty seats were held for “leaders” who filled them in when they returned from some fancy-pants dinner.) The occasion: a “Spring” program of Schumann’s Symphony #1 (titled “Spring"); Borodin’s ‘Polov’tsian Dances’; Stravinsky’s ‘Rite of Spring.’ A thrilling evening with Hugh Wolff and the NEC Philharmonia. The place exploded with applause and shouts at the conclusion. Rightly so.