What of Words and What of Song Juliet Fraser, vocalist With Mikael Rudolfsson, trombone, Helen Bledsoe, bass flute, and Uli Fussenegger, double bass NEOS Music    Soprano Juliet Fraser is one of very few performers who could successfully present the challenging program on What of Words and What of Song (NEOS Music). It consists of works by European composers born in the 1950s and 1960s: Rebecca Saunders, Enno Poppe, Beat Furrer, and Chaya Chernowin. Fraser doesn’t just sing them, she inhabits the pieces with encompassing dramatic commitment.    “O,” by Rebecca Saunders, features swooping glissandos and breath slides,