ME4 Ong started his music career as a piano teacher and a freelance lounge pianist. In 1990, he joined the SIR Band as a clarinettist, and obtained the Associated Board of the Royal Schools of Music Grade 8 certification within 3 years.

In 1992, ME4 Ong was selected to attend the Assistant Band Leader Course at the Defence Force School of Music in Australia, where he studied conducting and music arrangement. He was appointed as the SIR Band's Assistant Band Sergeant Major on his return and was actively involved in arranging music for the wind band, combo band, and chamber ensembles. During the merger of the tri-service bands in 1994 and the SAF Band's transformation, ME4 Ong also helped to formalise new administrative and operating procedures in the bands.

In his years of service, he has held several key appointments in the SAF Band – from Concertmaster to Woodwind Group Leader; Section Leader; and Combo IC.