Hirtz began playing with the PSO in 1948. At the beginning of his career, according to the Tribune-Review, he shared a music stand with Lorin Maazel, later music director of the PSO and currently music director of the New York Philharmonic.
Hirtz retired in 1992, having performed under music directors William Steinberg, Andr_ Previn, and Maazel. He continued to appear as a substitute through 2002.