To single out special triumphs from the singing that Shirley Verrett offered throughout her Saturday night concert in the Kennedy Center seems almost a slight to the rest of the elegant program.

But there were moments of such particulr radiance that they deserve singular notice. The totality with which she moved through "Befreit" by Richard Strauss was everything called for in that remarkable song.

Soon thereafter Verett provided a different kind of brilliance, with her ease in the agile phrases of the "Alleluia" that concludes Mozart's famous motet, "Exsulate, jubilate." And at the end of that passage there was a high C of dazzling purity and ease.

Shortly after intermission, another of these high points occurred in the hushed rapture with which Verrett sang Hall Johnson's arrangement of the spiritual, "City Called Heaven." There were, however, only some of the moments in an evening of superb song.

At times Verrett takes rather calmly passages - such as some in "O Had I Jubal's Lyre" - that would profit from a greater dramatic accent. And while her "Ruhe, meine Seele," by Strauss was full of poetic inflection, it, too, makes greater impact.

Verrett's voice was in exquisite form all Saturday evening, and her singing in English, Italian, Latin, French and German a continuing reward. She owes herself and her audience a pianist able to support her with more appropriate sonorities than Warren Wilson, whose playing In Mozart was an embarrassment.