Isaac began music at age 4½ and has since performed and studied many genres of music, playing in jazz bands on bass and piano, in string quartets on cello, in rock bands on guitar and keyboard, and as a freelance accompanist on piano. In 2009, Isaac worked on secondement with Sydney Theatre Company on Spring Awakening, and began work as an arranger for Peter Cousens and Anne-Maree McDonald. He worked with Peter and Anne-Maree again when he was the repetiteur and pianist for the Australian concert production of the musical Floyd Collins. In 2010, his composition Threesome, for electric trio, was accepted into the 2010 ISCM / Aurora Festival. He has also worked for New Musicals Australia as a musical director, workshopping A Little Touch of Chaos, a new musical by James Miller and Peter Rutherford. Isaac is also the musical director and pianist for a monthly cabaret show called The Divine Miss Bette, a tribute to Bette Midler. He is also the pianist for Monday Night Live, an open-mic night at Slide Bar in Sydney, and currently plays as a deputy keyboardist in Mary Poppins for Disney / Cameron Mackintosh.
Isaac plays a Fender American Deluxe Stratocaster.