[1] Massaro began his career in California working as an accompanist and coach for the Los Angeles Opera Repertory Theatre.
He coached Lieder repertoire with the great soprano Elisabeth Schwarzkopf at the Britten-Pears School in Aldeburgh, the Frankfurt Opera and also at her home in Zurich.
During his time in New York, Massaro had the fortune of working closely with many wonderful singers and conductors including Leonard Bernstein, assisting him with his last opera A Quiet Place.
He met Zubin Mehta for whom he served as a conducting assistant during a production of Puccini's Madama Butterfly with the Israel Philharmonic.
As a recitalist, Massaro has accompanied several artists including his wife, Gail Dubinbaum, throughout the United States and Canada.