His work focuses on the relationship between music and identity. His publication, Birds of Fire: Jazz, Rock, Funk and the Creation of Fusion (Duke University Press), was considered the most accomplished monograph of the contenders. Fellezs’ books frames fusion (jazz-rock-funk) music of the 1970s with insights drawn from ethnic studies, jazz studies, and popular music studies. He has also published articles on African American musicians in heavy metal and enka (Japanese popular music genre) and Asian American jazz musicians.