who sang the song jump for the cubs theme song a couple of years ago or somin like that?

Question

and he was on a talk show just a couple of nights ago i think on jay leno and he sang it with other people doin like fiddles and etc stuff like that right by him and he's kind of old

Answer 1

You're thinking of the first frontman for Van Halen, David Lee Roth:
http://en.wikipedia.org/wiki/David_Lee_Roth
http://www.davidleeroth.com/

The song you heard is just one from a collaboration he was part of called "Strummin with the Devil" - an album full of VH covers done all bluegrassy:
http://www.strumminwiththedevil.com/web/page.asp

Answer 2

it was van halen in 1984

Answer 3

That was Van Halen. So glad they don't use it anymore, it was gagging me!