Musician and actor Jack Sheldon, well known for his voice work on Schoolhouse Rock! and his decades-long stint as Merv Griffin's sidekick, has sadly passed away. According to his longtime partner and manager, Dianne Jimenez, Sheldon died on Friday due to natural causes, though no other details surrounding his passing were immediately made clear. The legendary performer was 88 years old.

Born in 1931, Jack Sheldon took an interest in performing early in life. After working as a professional trumpet player, Sheldon joined the Air Force and continued to perform in military bands. Sheldon then performed and recorded with many established jazz artists in the '50s, further shining his star power. His talents caught the attention of television producers, leading to Sheldon joining The Merv Griffin Show as Griffin's sidekick in 1962 where he remained for most of the show's entire duration until 1986.

Sheldon's distinct voice also led to his prowess as an excellent voice actor as well. He is very fondly remembered for voicing major characters in classic Schoolhouse Rock! cartoons, including "Conjunction Junction" and "I'm Just a Bill." For the latter, Sheldon sang as the voice of the titular Bill, with his son John voicing the young boy who speaks to him. Decades later, Sheldon would poke some fun at the role by reprising the voice of the Bill for parody segments on The Simpsons and Family Guy.

As a voice actor, Sheldon is also known for voicing Louie the Lightning Bug in a series of animated public service announcements in the '80s created to promote safety with electricity. He also voiced the Sensitive Man in an episode of Johnny Bravo. On the small screen, Sheldon has also appeared on multiple classic television shows, which includes roles on The Cara Williams Show, Dragnet, and Star Trek: The Next Generation. Sheldon also even starred as an accountant on the run from the mob in his own 16-episode sitcom called Run, Buddy, Run.

Sheldon's music has also been featured in many movies, and he has been featured in a handful of films as well. He played trumpet player Ruffles Reedy in the 1994 movie Radioland Murders, which saw his character meeting a grim fate. Additionally, Sheldon can be seen in the documentaries He was also featured in the Oscar-nominated documentary Let's Get Lost which tells the story of jazz musician Chet Baker. Additionally, Sheldon is the subject of his own 2008 documentary Trying to get Good: the Jazz Odyssey of Jack Sheldon, which included interviews with Merv Griffin, Clint Eastwood, and Billy Crystal. The doc won many jury and audience awards during its run in the film festival circuit.

Sheldon's survivors include his children, Jessie and John, and his longtime partner, Dianne Jimenez. Our thoughts our with them at this time and we offer our condolences. May Sheldon rest in peace as his legacy will continue to live on forever. You can watch the original Schoolhouse Rock! video for "I'm Just a Bill" below. This news comes to us from the Associated Press.