Born in Sarvar, Hungary, Marosi’s musical education began at the age of five, and continued at the Music Gymnasium, where he majored on both piano and trombone. He studied conducting at the Liszt Academy of Music with Tamas Breitner, the director of the Pecs Opera.
From 1982 to 1997 Marosi worked as the conductor of the Hungarian Central Army Orchestra. During this period he recorded a number of works by Liszt and several contemporary Hungarian composers. He also conducted his ensemble for radio and television productions and toured with the group throughout Europe.
His book,The History of the Military Music in Hungary from 1741-1945, was published in 2011.