Early on in his career Kyle starred in a 7-Up commercial.
Kyle and Jack both had a cameo in the Foo Fighters music video 'Learn To Fly' before Dave Grohl returned the compliment by playing drums for Tenacious D. He also starred as the devil in their music video 'Tribute' and then later in their film 'Tenacious D in: The Pick of Destiny'.
Before trying is hand at guitar, Gass also dabbled with the flute and the saxophone.
Kyle once appeared in the Good Charlotte music video for 'Lifestyles of the Rich And Famous' as a lawyer questioning a dog.
He taught Jack Black how to play guitar and this was how they came to form Tenacious D.
He and Jack Black didn't see eye-to-eye when they first met but soon set aside their differences to become great friends.
As well as his work in Tenacious D he also provides guitar and vocals for a group called Trainwreck.
He and Jack Black starred in the 2006 movie Tenacious D in: The Pick of Destiny as themselves.
Kyle: I still do television, like Undeclared. We both have stuff going on. It's really all a commutation.
Kyle: (referring to Jack Black) I was much older than Jack, so I tried to take sort of a high status position.
Kyle: (on Tenacious D's arrival in Australia prior to their concert) If Zoo TV was crossed with Jesus Christ Superstar and you took out most of the elements of those shows, you would almost have the accurate distillation of our full-on rock experience. I want Australia to know we are losing money on this tour because it is so big and you can tell Russell Crowe we will crush him with our 60-odd feet of grunt. Crush him like a bug.
Kyle: I think it's what makes us a little different from some guitar comics. We love music and just try to make really great songs.
Kyle: (talking about Tenacious D in "The Pick of Destiny") The opening scene is mind-blowing and I just sometimes get a little sad when it stops. That's when I come on.
Kyle: When I think Nirvana's drummer is our drummer then it's weird and I'll never get over that.
Kyle: (referring to himself and Jack) We had a photo shoot at MTV where they wanted us to make out. And we did. But just very briefly. No tongue.
Kyle: I love soft rock and pop. I'm not really a hard rocker; I'm more of a James Taylor kind of guy.
Kyle: I'll go to a coffee shop and someone will say: "You rock!" And I remember how awesome I am.
Kyle: We try to write the best songs ever and they come out kind of funny.
Kyle: I wore glasses and thought I was smart and talented you know, but then I sort of got more into sports and kind of became more of a renaissance character aiming to excel in many different areas.