The Finnish Consulate surely outdid itself in subsdizing this striking visual accompaniment to the New Jersey Symphony's "Northern Lights Festival." Pekka Kuusisto's performance of the Sibelius Violin Concerto on Friday night, before the snow began to fall, was a wonderfully free, vital interpretation, poised between Bachian cogitation and folk fiddling. He's also a charismatic, funny guy who had the audience in stitches with his absurdist summary of the Kalevala epic: "It doesn't take a rocket scientist to know that trying to kill the Swan of Death is maybe not the smartest project." Any American orchestra would want to have him, for the playing and talking alike.