As a young teenager, Nelson founded and was the front man for the underground band ‘Mango Bang’, formed in the heart of Venice California. They played extensively in the Los Angeles underground scene for 15 years during the time period where hip-hop, ska, reggae, rock, punk, and Latin soul were greatly on the rise. Marquez and his band toured internationally and shared the stage with artists and bands such as Fela Kuti, The Wailers, Earth, Wind, and Fire, Mongo Santamaria, Ruben Blades, The Bangles, Burning Spear, and Armando Peraza.

Nelson is also an original band member of Andy Garcia and the CineSon All Stars. This band was created to honor the legacy of legendary bassist and composer Israel “Cachao” Lopez’s compositions and the heritage of Cuban music. Nelson worked on five albums with Cachao and his band, which were endowed with a 1994 Grammy Award for Volume I of “Cachao Master Sessions” and a nomination for Volume II in 1995.

After his solo album release in 2024 of ‘Turn the Light On’. Nelson has returned to the studio and is currently working on solo and collaborative projects that is expanding his skills as a producer, vocalist, and multi-instrumentalist.