Developing his craft in various playing situations, Dennis received numerous awards such as "Who's Who in Music", 1979; National Endowment for the Arts grant for composition in 1983; and in 1992; "Outstanding Alumni" from the University of Nevada, Las Vegas. While attending UNLV, he was a member of the acclaimed UNLV Jazz Ensemble where his drumming and arranging skills caught the attention of vocalist Joe Williams.
In 1981, at 19 years of age, Dennis moved to New York City and landed a gig as a drummer on Broadway. His Broadway credits include "The First" and "A Chorus Line". In January of 1983, Dennis joined the Count Basie Orchestra on the personal recommendation of Mr. Williams. He would become the youngest member of the orchestra and the last drummer to be hired by Mr. Basie personally.