Marcus first took up the saxophone in 1984 at age 12 under the direction of Gary Bailey at the Texas School for the Blind in Austin, Texas. Showing an almost immediate aptitude for the instrument, he set about on a middle and high school career studded with achievements, including 2 Louis Armstrong Jazz Awards. Adding to his studies with private music lessons from instructors at the University of Texas and summer tours with state-sponsored ensembles, by the age of 16 he had already performed in both the Montreaux Jazz Festival in 1987 and the Montreal Jazz Festival in 1988. It was also during this time that he began playing around the city of Austin, sitting in any time he could with his friends in the popular local Soul/R&B band Blue Mist.

   In 1990, Marcus moved to Boston, Massachusetts to study at the Berklee College of Music. Here he focused heavily on ear training, music theory, and reportoire, as well as studied privately with the likes of Andy McGhee (Lionel Hampton/Woody Herman) and Bill Pierce (Art Blakey/Tony Williams). Leaving Berklee for a short time in 1992, he moved to the Birmingham, Alabama area to tour the Southeast U.S. with his own band, Midnite Rain as part of the budding "Jam-band" movement of the early '90s. During this time, he also enjoyed a brief stint touring with Ryko recording artists The Barking Tribe, opening for such acts as Cowboy Mouth and The Reverend Horton Heat. Marcus returned to Berklee in 1994 to resume his studies, and began playing bass in a local rock band, Boomahead, in addition to working on the Boston studio scene as a saxophonist. He did this until 1995, when he once again moved to Austin, Texas, where he still lives today.

   For the last 25 years, Marcus has been an active resident of the vibrant and diverse Austin music scene, performing and recording with bands of all genres. As a performer, he has been a part of hip-hop/funk outfit Retarted Elf and has toured with reggae artists Root 1, as well as made appearances with everyone from local legends Bob Schneider and Carolyn Wonderland to national superstars Parliament Funkadellic. His jazz-funk quartet Gnappy performed and toured across the U.S. from 1997 to 2007, sharing bills with acts like Col. Bruce Hampton, the Wailers, and Papa Grows Funk. Written up in national publications such as JazzTimes, they were also featured on prominent music websites Napster and The Homegrown Music Network. Gnappy recorded 3 albums--the third of which, "UnLoadEd", spent 8 weeks on the CMJ Jazz Top 40 as well as received extensive airplay on radio stations around the country and can still be heard on SiriusXM, Pandora, Apple Music, and Spotify.

   Currently Marcus works steadily with several projects about Austin, from variety bands like the Argyles and The Gladiators Big Band to neo-funk powerhouses The Capitol and A-Town Getdown. His 3-piece horn section, Hellfire Horns, provides performance and recording support for both local and touring acts, and every spring finds him in the pit orchestra for the Adderley School Youth Ensemble Theatre. Marcus also works as a bassist, turning the hobby he picked up in high school into even more professional collaborations with bands such as psycho-jazzers Doctor Darkness and Houston metal trio Your Amsterdam. Along with all of this, he still finds time to appear at shows and on recordings as a sideman with many other well-known locals; including D-Madness, Akina Adderley & the Vintage Playboys, Flyjack, Zack Morgan & Friends, HeartByrne, and Big Wy's Brass Band.