Though changing a program is an artist's prerogative, soprano Donna Robin may have done herself a disservice by overuse of the privilege at the Pan American Union last night. She seemed to put both herself and the audience on the wrong foot when she began by reading rapidly through a list of changes. A general puzzlement over just what she had said disrupted the communication between artist and listener during the opening section of the concert.

It was a pity. Once she had warmed up and the audience had figured out where she was -- which occurred somewhere toward the end of the Villa-Lobos selections -- Robin revealed a number of assets. She has developed a smoothly flowing, flexible voice that can move up into the stratospheric range with ease and accuracy. Her liquid shaping of the soaring lines in a series of Ned Rorem songs proved to be the evening's high point. Rorem's music also provoked an expressive precision lacking in most of the other material.

Too often Robin confined herself to broad contours, missing many details that would intensify her art. With a strong instrument at her command, she needs now to find within the music and herself those nuances that can transform a pleasant performance into a compelling one.

Pianist Robert Parris provided Robin with a superb framework, offering a splendid example of how to project the subtleties of a score.