Complex sentence: Elsas has also had an extensive voice-over career that includes numerous projects for HBO, Cinemax, Showtime, The Movie Channel and he is also known as "The Voice Of Rock History" at the Museum at Bethel Woods.
Split into simpler sentences: Elsas has also had an extensive voice-over career. He's done numerous projects for HBO, Cinemax, Showtime, The Movie Channel and is known as "The Voice Of Rock History" at the Museum at Bethel Woods.