
He was born in Ridgecrest, California, and grew up in the San Diego area, where he got involved in the local punk scene.
He formed the alternative pop duo Simple Creatures (with Alex Gaskarth) and has collaborated on side projects and studio work with other artists.
Mark is best known as a bassist and singer, but he also plays guitar, writes songs, and works in production roles.
His basslines are melodic and punchy, designed to support catchy hooks. He keeps parts simple and direct to serve the song’s energy and sing-along quality.
Most of his well-known songs are collaborative—he often develops melodies and lyrics with bandmates but also brings fully formed ideas at times.
In 2021 he announced a lymphoma diagnosis and underwent treatment; he later reported that he responded well and entered remission after therapy.
He draws on punk-rock energy, pop melody, personal experiences, and humor—focusing on honest, accessible lyrics and memorable hooks.