He has been hired by American Express, Procter and Gamble, Kraft Foods, Time Inc. and Lancome to support their advertising efforts. His distinctive voice has been featured in commercial spots from Sprite, Honey Bunches of Oats, Oil of Olay, Imitrex and Vaseline Intensive Care, among others. His promos and narrations have been heard on NBC, CBS, ABC, HBO, Showtime, Cinemax, A&E, PBS, USA and more.

Dennis has been the announcer for the Rock and Roll Hall of Fame broadcasts, VH1’s Concert of the Century at the White House, and is featured as the “Voice of Rock History” in the Museum at Bethel Woods – the story of the Sixties and Woodstock. He was also the narrator of Discovery Magazine for the Discovery Channel and the voice of the Smithsonian Channel.