Portman's musical career began during his high school years in 1979, when he played in a band called the Bent Nails alongside future Mr. T Experience bass player Byron Stamatatos.

While a student there he hosted a program on campus radio station KALX which prominently featured local punk rock music, and met fellow DJ Jon Von Zelowitz.

They began to build a local following through tours and airplay on college radio stations and quickly became part of the thriving late-1980s Bay Area punk rock movement centered around the 924 Gilman Street venue and the Lookout!

At this time Portman briefly also played drums with the band Sweet Baby, but quickly returned to his main focus The Mr. T Experience, who released their second album Night Shift at the Thrill Factory in 1988.

Portman's musical style is generally characterized as pop punk, heavily influenced by the Ramones and other melodic rock groups.

His compositions cover a variety of topics but are concerned primarily with personal relationships; he is known to introduce much of his material with the throwaway line "This is a song about a girl."

Over the years his other musical tastes and interests have pushed the band to explore many styles, branching out from the Bay Area pop punk sound which he helped define.

Portman's solo recordings have further explored these other styles and influences, including country, bossa nova, Rock & Roll, and 1960s beat music.

Portman appeared on Ken Reid's TV Guidance Counselor podcast on February 9, 2017 in an episode recorded live at SF Sketchfest.